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  • 1.
    Abitbol, Tiffany
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. The Hebrew University of Jerusalem, Israel..
    Kam, Doron
    The Hebrew University of Jerusalem, Israel..
    Levi-Kalisman, Yael
    The Hebrew University of Jerusalem, Israel..
    Gray, Derek G
    McGill University, Canada.
    Shoseyov, Oded
    The Hebrew University of Jerusalem, Israel..
    Surface Charge Influence on the Phase Separation and Viscosity of Cellulose Nanocrystals.2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 13, p. 3925-3933Article in journal (Refereed)
    Abstract [en]

    counterions in the suspensions. The results suggest that there is a threshold surface charge density (∼0.3%S) above which effective volume considerations are dominant across the concentration range relevant to liquid crystalline phase formation. Above this threshold value, phase separation occurs at the same effective volume fraction of CNCs (∼10 vol %), with a corresponding increase in critical concentration due to the decrease in effective diameter that occurs with increasing surface charge. Below or near this threshold value, the formation of end-to-end aggregates may favor gelation and interfere with ordered phase formation.

  • 2.
    Andersson, I. M.
    et al.
    Lund University, Sweden.
    Glantz, M.
    Lund University, Sweden.
    Alexander, M.
    Arla Foods Ingredients Group P/S, Denmark.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Paulsson, M.
    Lund University, Sweden.
    Bergenståhl, B.
    Lund University, Sweden.
    Impact of surface properties on morphology of spray-dried milk serum protein/lactose systems2018In: International Dairy Journal, ISSN 0958-6946, E-ISSN 1879-0143, Vol. 85, p. 86-95Article in journal (Refereed)
    Abstract [en]

    This study investigated milk serum protein concentrate/lactose systems with varying ratios and how the morphology of the spray-dried particles of these systems could be described by the surface properties of the feed as well as the protein surface coverage of the particles. An extrapolation of the surface pressure of the feed to 0.3 s, the approximate time for molecular diffusion in an atomised droplet in the spray-dryer, showed a relationship with the particle morphology. At low protein concentrations (<1%), the particles were almost totally smooth. At higher protein concentrations (≥1%), the particles became dented and ridged, and these tended to become deeper and thicker as the protein concentration increased. It is suggested that the surface pressure of the feed at low protein concentrations is the most prominent surface property, whereas the modulus of elasticity seems to be the most prominent surface property for particle surface deformation at higher protein concentrations.

  • 3.
    Andersson, I. M.
    et al.
    Lund University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Alexander, M.
    Arla Foods Ingredients Group P/S, Denmark.
    Hellström, N.
    Lund University, Sweden.
    Glantz, Maria
    Lund University, Sweden.
    Paulsson, M.
    Lund University, Sweden.
    Bergenståhl, Björn
    Lund University, Sweden.
    Impact of protein surface coverage and layer thickness on rehydration characteristics of milk serum protein/lactose powder particles2019In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 561, p. 395-404Article in journal (Refereed)
    Abstract [en]

    Spray-dried powders were produced from milk serum protein concentrate and lactose in varying ratios, and the rehydration characteristics of the powders were evaluated. The dissolution rate was estimated with a flow-cell based technique, and the external and internal distribution of the powder components were evaluated with X-ray photoelectron spectroscopy and confocal Raman microscopy, respectively. The surface of the powder particles is more or less covered by a thin protein layer. A phase segregation between protein and lactose is observed in the interior of the particle resulting in a protein rich layer in the vicinity of the surface. However, the protein layer in the vicinity of the particle surface tends to become thinner as the bulk protein concentration increases in the powders (from 10 to 60% w/w). The time for the spontaneous imbibition to occur show a linear correlation with the protein surface coverage. The dissolution rate of powders containing 0.1% w/w protein is around 60 times faster than for a powder containing 1% w/w protein but the dissolution rate of powders containing 1% and 100% w/w differ only by a factor of 2. Thus, it is suggested that the outer protein layer becomes denser at the interface as the protein content increases in the powders, thereby causing poorer rehydration characteristics of the powders (especially for low protein concentrations 0.1–1% w/w). This insight has relevance for the formulation of whey protein powders with improved rehydration characteristics. © 2018 Elsevier B.V.

  • 4.
    Anheden, Marie
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy.
    Uhlin, Anders
    RISE - Research Institutes of Sweden, Bioeconomy.
    Wolf, Jens
    RISE - Research Institutes of Sweden, Bioeconomy.
    Hedberg, Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Berg, Robert
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ankner, Tobias
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Berglin, Niklas
    NiNa Innovation and ÅF Industry, Sweden.
    von Schenck, Anna
    NiNa Innovation and ÅF Industry, Sweden.
    Larsson, Anders L
    Valmet AB, Sweden.
    Guimaraes, Matheus
    Fibria, Sweden.
    Fiskerud, Maria
    Fly Green Fund and Karlstad Airport, Sweden.
    Andersson, Stefan
    RISE - Research Institutes of Sweden, Bioeconomy.
    Value chain for production of bio-oil from kraft lignin for use as bio-jet fuel2017In: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017: NWBC 2017, Stockholm: RISE Bioekonomi , 2017, p. 104-109Conference paper (Refereed)
    Abstract [en]

    The LignoJet project aimed to achieve an intermediate lignin-oil product miscible with fossil feedstock and with a significantly reduced oxygen content. A technical concept for production has been studied that involves combined catalysed depolymerisation and hydrodeoxygenation, so called hydrogenolytic depolymerisation, of kraft lignin. Kraft lignin was separated through membrane ultrafiltration from softwood and eucalyptus black liquor followed by precipitation through LignoBoost technology. A difference in lignin properties was observed between ultrafiltration of softwood and eucalyptus black liquor through 15 and 150kDa ceramic membranes. Lignin-oils with similar oxygen content were produced regardless of origin and fractionation technique. A lignin-oil with favourable properties as precursor for refinery integration for jet fuel production as produced in small-scale batch experiments using nickel-based catalyst. Stable pumpable oils with melting point of less than 25-50 deg C and with 20-30% lower oxygen content and aromatic content were obtained that would be suitable as jet fuel precursors. The estimated production cost was found to be competitive with that of other liquid biofuels, while additional revenues could potentially be achieved by also producing chemical and materials from suitable fractions of the lignin-oil.

  • 5.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Nordgren, Niklas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Schuleit, Michael
    Novartis Pharma AG, Switzerland.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    AFM Colloidal Probe Measurements Implicate Capillary Condensation in Punch-Particle Surface Interactions during Tableting2017In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 46, p. 13180-13188Article in journal (Refereed)
    Abstract [en]

    Adhesion of the powders to the punches is a common issue during tableting. This phenomenon is known as sticking and affects the quality of the manufactured tablets. Defective tablets increase the cost of the manufacturing process. Thus, the ability to predict the tableting performance of the formulation blend before the process is scaled-up is important. The adhesive propensity of the powder to the tableting tools is mostly governed by the surface-surface adhesive interactions. Atomic force microscopy (AFM) colloidal probe is a surface characterization technique that allows the measurement of the adhesive interactions between two materials of interest. In this study, AFM steel colloidal probe measurements were performed on ibuprofen, MCC (microcrystalline cellulose), α-lactose monohydrate, and spray-dried lactose particles as an approach to modeling the punch-particle surface interactions during tableting. The excipients (lactose and MCC) showed constant, small, attractive, and adhesive forces toward the steel surface after a repeated number of contacts. In comparison, ibuprofen displayed a much larger attractive and adhesive interaction increasing over time both in magnitude and in jump-in/jump-out separation distance. The type of interaction acting on the excipient-steel interface can be related to a van der Waals force, which is relatively weak and short-ranged. By contrast, the ibuprofen-steel interaction is described by a capillary force profile. Even though ibuprofen is not highly hydrophilic, the relatively smooth surfaces of the crystals allow "contact flooding" upon contact with the steel probe. Capillary forces increase because of the "harvesting" of moisture - due to the fast condensation kinetics - leaving a residual condensate that contributes to increase the interaction force after each consecutive contact. Local asperity contacts on the more hydrophilic surface of the excipients prevent the flooding of the contact zone, and there is no such adhesive effect under the same ambient conditions. The markedly different behavior detected by force measurements clearly shows the sticky and nonsticky propensity of the materials and allows a mechanistic description.

  • 6.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Pazesh, Samaneh
    Uppsala University, Sweden.
    Nordgren, Niclas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Schuleit, Micheal
    Novartis Pharma AG, Switzerland.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Alderborn, Göran
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Milling induced amorphisation and recrystallization of α-lactose monohydrate2018In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 537, no 1-2, p. 140-147Article in journal (Refereed)
    Abstract [en]

    Preprocessing of pharmaceutical powders is a common procedure to condition the materials for a better manufacturing performance. However, such operations may induce undesired material properties modifications when conditioning particle size through milling, for example. Modification of both surface and bulk material structure will change the material properties, thus affecting the processability of the powder. Hence it is essential to control the material transformations that occur during milling. Topographical and mechanical changes in surface properties can be a preliminary indication of further material transformations. Therefore a surface evaluation of the α-lactose monohydrate after short and prolonged milling times has been performed. Unprocessed α-lactose monohydrate and spray dried lactose were evaluated in parallel to the milled samples as reference examples of the crystalline and amorphous lactose structure. Morphological differences between unprocessed α-lactose, 1 h and 20 h milled lactose and spray dried lactose were detected from SEM and AFM images. Additionally, AFM was used to simultaneously characterize particle surface amorphicity by measuring energy dissipation. Extensive surface amorphicity was detected after 1 h of milling while prolonged milling times showed only a moderate particle surface amorphisation. Bulk material characterization performed with DSC indicated a partial amorphicity for the 1 h milled lactose and a fully amorphous thermal profile for the 20 h milled lactose. The temperature profiles however, were shifted somewhat in the comparison to the amorphous reference, particularly after extended milling, suggesting a different amorphous state compared to the spray-dried material. Water loss during milling was measured with TGA, showing lower water content for the lactose amorphized through milling compared to spray dried amorphous lactose. The combined results suggest a surface-bulk propagation of the amorphicity during milling in combination with a different amorphous structural conformation to that of the amorphous spray dried lactose. The hardened surface may be due to either surface crystallization of lactose or to formation of a low-water glass transition.

  • 7.
    Berg, Robert
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Process och Pharmaceuticals Development.
    Bergman, Jan
    Karolinska Institute, Sweden.
    Synthesis of thieno[2,3-b]indole-2,3-diones and their ring expansions induced by diazomethane2017In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 73, no 38, p. 5654-5658Article in journal (Refereed)
    Abstract [en]

    Indole-2-thione 3 reacted quickly with oxalyl chloride to yield thieno[2,3-b]indole-2,3-dione 4 together with the isomer thiazolo[3,2-a]indole-2,3-dione 5. These thieno[2,3-b]indole-2,3diones underwent ring expansions when treated with diazomethane and e.g. thieno[2,3-b]indole-2,3-dione 4 gave the thiopyrano derivative 16, after two insertions.

  • 8.
    Bełdowski, Piotr
    et al.
    UTP University of Science and Technology, Poland.
    Weber, Piotr
    Gdansk University of Technology, Poland.
    Dedinaite, Andra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Claesson, Per M
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Gadomski, Adam
    UTP University of Science and Technology, Poland.
    Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment2018In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 14, no 44, p. 8997-9004Article in journal (Refereed)
    Abstract [en]

    Hyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and the small world network approach to investigate dynamic couplings using a distance map applied to oxygen atoms in a chain of hyaluronic acid in the presence of phospholipids and water. The distance characterizing the coupling can be defined in various ways to bring out the most evident differences between various scenarios of the polymer chain conformation We show herein a physical distance understood as H-bond length and classes of these distances which are defined in a coarse-grained picture of the molecule. Simulation results indicate that addition of phospholipids has little influence on hyaluronic acid crosslinking. However, longer chains and addition of lipids promote appreciably long lasting (resilient) networks that may be of importance in biological systems. Specific sites for hydrogen bonding of phospholipids to hyaluronic acid have also been identified.

  • 9.
    Boge, Lukas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Hallstensson, Karin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Johansson, Jenny
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Andersson, Therese
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Davoudi, Mina
    Lund University, Sweden.
    Larsson, Per Tomas
    RISE - Research Institutes of Sweden, Bioeconomy.
    Mahlapuu, Margit
    Promore Pharma AB, Sweden; University of Gothenburg, Sweden.
    Håkansson, Joakim
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Cubosomes for topical delivery of the antimicrobial peptide LL-372018In: European journal of pharmaceutics and biopharmaceutics, ISSN 0939-6411, E-ISSN 1873-3441, Vol. 134, p. 60-67, article id S0939-6411(18)31196-2Article in journal (Refereed)
    Abstract [en]

    In this study, the use of cubosomes for topical delivery of the antimicrobial peptide (AMP) LL-37 was investigated. Topical delivery of AMPs is of great interest for treatment of skin infections caused by bacteria, such as Staphylococcus aureus. AMP containing cubosomes were produced by three different preparation protocols and compared: i) pre-loading, where LL-37 was incorporated into a liquid crystalline gel, which thereafter was dispersed into nanoparticles, ii) post-loading, where LL-37 was let to adsorb onto pre-formed cubosomes, and iii) hydrotrope-loading, where LL-37 was incorporated during the spontaneously formed cubosomes in an ethanol/glycerol monooleate mixture. Particle size and size distribution were analyzed using dynamic light scattering (DLS), liquid crystalline structure by small angle x-ray scattering (SAXS) and release of LL-37 by a fluorescamine assay. Proteolytic protection of LL-37 as well as bactericidal effect after enzyme exposure was investigated. The skin irritation potential of cubosomes was examined by an in vitro epidermis model. Finally, the bacterial killing property of the cubosomes was examined by an ex vivo pig skin wound infection model with Staphylococcus aureus. Data showed that a high loading of LL-37 induced formation of vesicles in case of cubosomes prepared by sonication (pre-loading). No release of LL-37 was observed from the cubosomes, indicating strong association of the peptide to the particles. Proteolysis studies showed that LL-37 was fully protected against enzymatic attacks while associated with the cubosomes, also denoting strong association of the peptide to the particles. As a consequence, bactericidal effect after enzyme exposure remained, compared to pure LL-37 which was subjected to proteolysis. No skin irritation potential of the cubosomes was found, thus enabling for topical administration. The ex vivo wound infection model showed that LL-37 in pre-loaded cubosomes killed bacteria most efficient.

  • 10.
    Boge, Lukas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Västberg, Amanda
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Umerska, Anita
    Université Bretagne Loire, France.
    Bysell, Helena
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Eriksson, Jonny
    Uppsala University, Sweden.
    Edwards, Katarina
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Freeze-dried and re-hydrated liquid crystalline nanoparticles stabilized with disaccharides for drug-delivery of the plectasin derivative AP114 antimicrobial peptide2018In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 522, p. 126-135Article in journal (Refereed)
    Abstract [en]

    Liquid crystalline nanoparticles (LCNPs), e.g. cubosomes and hexosomes, are receiving more and more attraction as drug delivery vehicles. Dry powder formulation that forms LCNPs upon hydration can be advantageous to make new routes of administration accessible. In this work, we investigate use of three disaccharides (lactose, trehalose and sucrose) as protective matrices for glycerol monooleate based LCNP forming powders produced by freeze-drying. Phase behavior, particle size and size distributions at the different preparation steps were monitored by small angle x-ray scattering (SAXS) and dynamic light scattering (DLS). Particle appearance was imaged by cryogenic transmission electron microscopy (cryo-TEM). Moreover, the therapeutic relevant antimicrobial peptide AP114 (plectasin derivative) was incorporated in the formulations. Peptide encapsulation and release as well as in vitro antibacterial effect were investigated. Results showed that all freeze-dried powders did form particles with liquid crystalline structure upon hydration. However, a phase transition from the bicontinuous cubic Pn3m to the reversed hexagonal was observed, as a consequence of sugar addition and the freeze-drying procedure. Data indicates that trehalose is the preferred choice of lyo-protectant in order to maintain a mono-modal particle size distribution. In addition, antimicrobial activity of AP114-containing formulations was found to be highest for the formulation containing trehalose. The release kinetics of AP114 from the nanoparticles was strongly affected by the dimensions of the hexagonal phase. Larger dimension of the hexagonal phase, significantly improved the release of AP114 and antimicrobial activity of the formulation.

  • 11.
    Both, E M
    et al.
    Wageningen University and Research, The Netherlands.
    Nuzzo, Marine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Boom, R M
    Wageningen University and Research, The Netherland.
    Schutyser, M A I
    Wageningen University and Research, The Netherland.
    Morphology development during single droplet drying of mixed component formulations and milk.2018In: Food Research International, ISSN 0963-9969, E-ISSN 1873-7145, Vol. 109, p. 448-454, article id S0963-9969(18)30328-4Article in journal (Refereed)
    Abstract [en]

    We report on the influence of selected components and their mixtures on the development of the morphology during drying of single droplets and extend the results to the morphology of whole milk powder particles. Sessile single droplet drying and acoustic levitation methods were employed to study single droplet drying. The influence of carbohydrates (lactose and maltodextrin DE12) and proteins (micellar casein or whey protein) on morphology development is very different, since upon concentration protein systems will jam and undergo a colloidal glass transition, whereas carbohydrate systems will gradually increase in viscosity as a consequence of the concentration. Whey protein gives relatively rigid shells due to jamming of the "hard sphere" proteins, while casein micelles behave as "soft spheres" that can deform after jamming, which gives flexibility to the shell during drying. The influence of the carbohydrates on the final morphology was found much larger than the influence of the proteins. Caseins influenced morphology only in mixtures with lactose at higher concentrations due to its high voluminosity. Similar observations were done for whole milk, where fat appeared to have no influence. With maltodextrin the influence of the casein was again observed in the shape and smoothness of wrinkles. Both sessile and levitated droplet drying methods provide a similar and consistent view on morphology development.

  • 12.
    Claesson, Per M.
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden.
    Li, Gen
    KTH Royal Institute of Technology, Sweden.
    He, Yunjian
    KTH Royal Institute of Technology, Sweden.
    Huang, Hui
    KTH Royal Institute of Technology, Sweden.
    Thorén, Per-Anders
    KTH Royal Institute of Technology, Sweden.
    Haviland, David B.
    From force curves to surface nanomechanical properties2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 35, p. 23642-23657Article in journal (Refereed)
    Abstract [en]

    Surface science, which spans the fields of chemistry, physics, biology and materials science, requires information to be obtained on the local properties and property variations across a surface. This has resulted in the development of different scanning probe methods that allow the measurement of local chemical composition and local electrical and mechanical properties. These techniques have led to rapid advancement in fundamental science with applications in areas such as composite materials, corrosion protection and wear resistance. In this perspective article, we focussed on the branch of scanning probe methods that allows the determination of surface nanomechanical properties. We discussed some different AFM-based modes that were used for these measurements and provided illustrative examples of the type of information that could be obtained. We also discussed some of the difficulties encountered during such studies.

  • 13.
    Dedinaite, Andra
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Synergies in lubrication2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 35, p. 23677-23689Article in journal (Refereed)
    Abstract [en]

    To slide surfaces against each other with application of a minimum force and minimum wear has been important since ancient times, and it remains equally important today. The use of oil-soluble lubricants is widely spread in technology, whereas living organisms have developed water-soluble lubricants to facilitate sliding motions. In this perspective article we focus on water-based lubrication in the boundary lubrication regime, and particularly lubrication synergies. This focus has, of course, found inspiration from the outstanding lubrication properties of synovial joints. It has ignited significant amount of research, mostly aimed at answering the question: Which molecule is the magic biolubricant? Different research groups have advocated different answers, and the debate has been intensive. In this article we argue that the question in itself is inappropriate. The relevant question is rather the following: How do molecules work in synergy to provide superior lubrication?

  • 14.
    Gao, Jiajia
    et al.
    KTH Royal Institue of Technology, Sweden.
    Fischer, Andreas
    KTH Royal Institue of Technology, Sweden.
    Svensson, Per H
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institue of Technology, Sweden.
    Kloo, Lars
    KTH Royal Institue of Technology, Sweden.
    Crystallography as forensic tool for understanding electrolyte degradation in dye-sensitized solar cells2017In: ChemistrySelect, Vol. 2, no 4, p. 1675-1680Article in journal (Refereed)
    Abstract [en]

    The precipitation of solid compounds from model electrolytes for liquid dye-sensitized solar cells has a story to tell regarding decomposition processes to be expected in such systems. Of course, the crystal lattice energy for a specific crystalline compounds plays a role in what compound that will eventually precipitate, but the compounds nevertheless serve as indicators for what type of processes that take place in the solar cell electrolytes upon ageing. From the compounds isolated in this study we learn that both ligand exchange processes, double-salt precipitation and oxidation are degradation processes that should not be overlooked when formulating efficient and stable electrolytes for this type of electrochemical system.

  • 15.
    Harra, Juha
    et al.
    Tampere University of Technology, Finland.
    Tuominen, Mikko
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Juuti, Paxton
    Tampere University of Technology, Finland.
    Rissler, Jenny
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Lund University, Sweden.
    Koivuluoto, Heli
    Tampere University of Technology, Finland.
    Haapanen, Janne
    Tampere University of Technology, Finland.
    Niemelä-Anttonen, Hanna
    Tampere University of Technology, Finland.
    Stenroos, Christian
    Tampere University of Technology, Finland.
    Teisala, Hannu
    Tampere University of Technology, Finland.
    Lahti, Johanna
    Tampere University of Technology, Finland.
    Kuusipalo, Jurkka
    Tampere University of Technology, Finland.
    Vuoristo, Petri
    Tampere University of Technology, Finland.
    Mäkelä, Jyrki M.
    Tampere University of Technology, Finland.
    Characteristics of nFOG, an aerosol-based wet thin film coating technique2018In: JCT Research, ISSN 1547-0091, E-ISSN 2168-8028, Vol. 15, no 3, p. 623-632Article in journal (Refereed)
    Abstract [en]

    An atmospheric pressure aerosol-based wet thin film coating technique called the nFOG is characterized and applied in polymer film coatings. In the nFOG, a fog of droplets is formed by two air-assist atomizers oriented toward each other inside a deposition chamber. The droplets settle gravitationally and deposit on a substrate, forming a wet film. In this study, the continuous deposition mode of the nFOG is explored. We determined the size distribution of water droplets inside the chamber in a wide side range of 0.1–100 µm and on the substrate using aerosol measurement instruments and optical microscopy, respectively. The droplet size distribution was found to be bimodal with droplets of approximately 30–50 µm contributing the most to the mass of the formed wet film. The complementary measurement methods allow us to estimate the role of different droplet deposition mechanisms. The obtained results suggest that the deposition velocity of the droplets is lower than the calculated terminal settling velocity, likely due to the flow fields inside the chamber. Furthermore, the mass flux of the droplets onto the substrate is determined to be in the order of 1 g/m3s, corresponding to a wet film growth rate of 1 µm/s. Finally, the nFOG technique is demonstrated by preparing polymer films with thicknesses in the range of approximately 0.1–20 µm.

  • 16.
    He, Yunjuan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Deltin, Tomas
    PTE Coatings AB, Sweden.
    Corkery, Robert W.
    KTH Royal Institute of Technology, Sweden.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Nano-scale mechanical and wear properties of a waterborne hydroxyacrylic-melamine anti-corrosion coating2018In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 457, p. 548-558Article in journal (Refereed)
    Abstract [en]

    Corrosion protection is commonly achieved by applying a thin polymer coating on the metal surface. Many studies have been devoted to local events occurring at the metal surface leading to local or general corrosion. In contrast, changes occurring in the organic coating after exposure to corrosive conditions are much less studied. In this article we outline how changes in the coating itself due to curing conditions, environmental and erosion effects can be investigated at the nanometer scale, and discuss how such changes would affect its corrosion protection performance. We focus on a waterborne hydroxyacrylic-melamine coating, showing high corrosion protection performance for carbon steel during long-term (≈35 days) exposure to 0.1 M NaCl solution. The effect of curing time on the conversion of the crosslinking reaction within the coating was evaluated by fourier transform infrared spectroscopy (FTIR); the wetting properties of the cured films were investigated by contact angle measurement, and the corrosion resistance was studied by electrochemical impedance spectroscopy (EIS). In particular, coating nanomechanical and wear properties before and after exposure to 0.1 M NaCl, were evaluated by atomic force microscopy (AFM). Fiber-like surface features were observed after exposure, which are suggested to arise due to diffusion of monomers or low molecular weight polymers to the surface. This may give rise to local weakening of the coating, leading to local corrosion after even longer exposure times. We also find a direct correlation between the stick-slip spacing during shearing and plastic deformation induced in the surface layer, giving rise to topographical ripple structures on the nanometer length scale.

  • 17.
    Hellsing, Maja
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Rennie, Adrian
    Uppsala University, Sweden.
    Rodal, Michael
    Biolin Scientific AB, Sweden.
    Höök, Fredrik
    Chalmers University of Technology, Sweden.
    Charged polystyrene nanoparticles near a SiO2/water interface2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827Article in journal (Refereed)
    Abstract [en]

    Quartz crystal microbalance with dissipation (QCM-D) monitoring is traditionally used to investigate adsorption processes at liquid-solid interfaces but has also been applied increasingly to characterize the viscoelastic properties of complex liquids. Here, we contribute new insights to the latter field by using QCM-D to investigate the structure near an interface and high-frequency viscoelastic properties of charge stabilized polystyrene particles (radius 37 nm) dispersed in pure water. The study reveals changes with increasing ionic-strength from the crystalline order at low salt concentration to that with a less-structured particle distribution at high ionic strength. Replacing pure water with an aqueous particle dispersion is due to an increased mass load expected to give rise to a decrease in frequency, f. In the present work increases in both f and dissipation, D, were observed on exchanging pure water for the particle dispersion at low ionic strength. However, the QCM-D data are still well-represented by a viscoelastic Voigt model, with the viscosity increasing from 1.0 to 1.3 mPa s as the particle volume fraction changed from 0.005 to 0.07. This increase is higher than predicted for dilute dispersions according to Einstein’s equation for the viscosity of non-interacting hard spheres particles in liquids but can be explained by the charge repulsion between the particles giving rise to a higher effective volume fraction. It is also concluded that the polystyrene particles did not adhere to the solid surface but rather were separated by a layer of pure dispersion medium. The QCM-D response was successfully represented using a viscoelastic Kelvin-Voigt model, from which it was concluded that the thickness of the Newtonian dispersion medium layer was of the order of the particle-particle bulk separation, in the range 50 to 250 nm and was observed to decrease with both particle concentration and with addition of salt. Similar anomalous frequency and dissipation responses have been seen previously for colloidal systems containing weakly adherent colloidal particles and bacteria and in these cases interpreted in terms of coupled resonators. We here demonstrate that surface attachment is not required for such phenomena to occur, but that a viscoelastic liquid separated from the oscillating surface by a thin Newtonian layer can give rise to very similar responses.

  • 18.
    Ivarsson, Magnus
    et al.
    University of Southern Denmark, Denmark ; Swedish Museum of Natural History, Sweden.
    Skogby, Henrik
    Swedish Museum of Natural History, Sweden.
    Phichaikamjornwut, Bongkot
    Srinakharinwirot University, Thailand.
    Bengtson, Stefan
    Swedish Museum of Natural History, Sweden.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ounchanum, Prayote
    Chiang Mai University, Thailand.
    Boonsoong, Apichet
    Chiang Mai University, Thailand.
    Kruachanta, Mingkhwan
    Chiang Mai University, Thailand.
    Marone, Federica
    Paul Scherrer Institute, Switzerland.
    Belivanova, Veneta
    Swedish Museum of Natural History, Sweden.
    Holmström, Sara
    Stockholm University, Sweden.
    Intricate tunnels in garnets from soils and river sediments in Thailand - Possible endolithic microborings.2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 8, article id e0200351Article in journal (Refereed)
    Abstract [en]

    Garnets from disparate geographical environments and origins such as oxidized soils and river sediments in Thailand host intricate systems of microsized tunnels that significantly decrease the quality and value of the garnets as gems. The origin of such tunneling has previously been attributed to abiotic processes. Here we present physical and chemical remains of endolithic microorganisms within the tunnels and discuss a probable biological origin of the tunnels. Extensive investigations with synchrotron-radiation X-ray tomographic microscopy (SRXTM) reveal morphological indications of biogenicity that further support a euendolithic interpretation. We suggest that the production of the tunnels was initiated by a combination of abiotic and biological processes, and that at later stages biological processes came to dominate. In environments such as river sediments and oxidized soils garnets are among the few remaining sources of bio-available Fe2+, thus it is likely that microbially mediated boring of the garnets has trophic reasons. Whatever the reason for garnet boring, the tunnel system represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack.

  • 19.
    Janosik, Tomasz
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Rannug, Agneta
    Karolinska Institutet, Sweden.
    Rannug, Ulf
    Stockholm University, Sweden.
    Wahlström, Niklas
    MagleChemoswed, Sweden.
    Slätt, Johnny
    KTH Royal Institute of Technology, Sweden.
    Bergman, Jan
    Karolinska Institutet, Sweden.
    Chemistry and Properties of Indolocarbazoles2018In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 118, no 18, p. 9058-9128Article in journal (Refereed)
    Abstract [en]

    The indolocarbazoles are an important class of nitrogen heterocycles which has evolved significantly in recent years, with numerous studies focusing on their diverse biological effects, or targeting new materials with potential applications in organic electronics. This review aims at providing a broad survey of the chemistry and properties of indolocarbazoles from an interdisciplinary point of view, with particular emphasis on practical synthetic aspects, as well as certain topics which have not been previously accounted for in detail, such as the occurrence, formation, biological activities, and metabolism of indolo[3,2- b]carbazoles. The literature of the past decade forms the basis of the text, which is further supplemented with older key references.

  • 20.
    Karlsson, Mikael
    et al.
    Chalmers University of Technology, Sweden.
    Abbas, Zareen
    University of Gothenburg, Sweden.
    Bordes, Romain
    Chalmers University of Technology, Sweden.
    Cao, Yu
    Chalmers University of Technology, Sweden.
    Larsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Rolland, Antonin
    Chalmers University of Technology, Sweden.
    Taylor, Phil
    AkzoNobel Decorative Paints, UK.
    Steenari, Britt-Marie
    Chalmers University of Technology, Sweden.
    Surface properties of recycled titanium oxide recovered from paint waste2018In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 125, p. 279-286Article in journal (Refereed)
    Abstract [en]

    Aluminium oxide coated rutile pigment was extracted from a paint matrix by means of a thermal recycling process. The objective was to investigate the effect of the recycling process on the surface properties of the pigment. The pigment was analysed using powder x-ray diffraction (XRD), surface area measurements (BET), laser diffraction for particle size analysis and X-ray photoelectron spectroscopy (XPS) before and after the recycling process. Investigations on the zeta potential and the surface charge were performed as well. It was concluded that the rutile crystalline core and the aluminium oxide coating of the pigment were still intact after the recycling process. The particle size distribution of the recycled pigment was slightly broader compared to the virgin pigment. The measured magnitude in zeta potential of the recycled pigment was lower than for the virgin pigment. This difference is thought to be caused by alteration in the surface hydroxyl concentration. Surface charge titrations showed differences between the virgin and the recycled pigment at alkaline pH and at low salt concentrations.

  • 21.
    Karlsson, Mikael C. F.
    et al.
    Chalmers University of Technology, Sweden.
    Abbas, Zareen
    University of Gothenburg, Sweden.
    Bordes, Romain
    Chalmers University of Technology, Sweden.
    Cao, Yu
    Chalmers University of Technology, Sweden.
    Larsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Taylor, Phil
    AkzoNobel Decorative Paints, UK.
    Steenari, Britt-Marie
    Chalmers University of Technology, Sweden.
    Characterisation of silicon, zirconium and aluminium coated titanium dioxide pigments recovered from paint waste2019In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 162, p. 145-152Article in journal (Refereed)
    Abstract [en]

    Titanium dioxide (TiO2) is the major white pigment used by the paint industry. However, the production of TiO2 is associated with a high carbon footprint. An alternative source of pigment could be created by developing a method to recover it from waste paint. In this paper two rutile pigments with different surface treatments were recovered from paint by a thermal recycling process. The pigments were analysed using powder x-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface area measurements (BET), laser diffraction for particle size analysis and zeta potential measurements before and after the recycling process. It was concluded that the rutile cores of both pigments were intact and there were no major changes in particle size distribution or surface charge for either pigment induced by the recycling process. However, XPS and zeta potential measurements showed that the surface coating of the pigments can be more or less degraded depending on the chemical nature, which might imply the need for further re-coating after-treatment. Another option would be to find another application for the pigment where the quality and function of the coating is of less importance.

  • 22.
    Karlsson, Mikael
    et al.
    Chalmers University of Technology, Sweden.
    Álvarez-Asencio, Ruben
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Bordes, Romain
    Chalmers University of Technology, Sweden.
    Larsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Taylor, Phil
    AkzoNobel Decorative Paints, UK.
    Steenari, Britt-Marie
    Chalmers University of Technology, Sweden.
    Characterization of paint formulated using secondary TiO2 pigments recovered from waste paint2018In: JCT Research, ISSN 1547-0091, E-ISSN 2168-8028Article in journal (Refereed)
    Abstract [en]

    The paint industry is continuously striving to reduce its environmental impact, especially when it comes to the major virgin white pigment, titanium dioxide (TiO2). In this work, recycled TiO2 pigment was used in a paint formulation as a replacement for pigment made from virgin raw materials. The paint was evaluated based on pH, Stormer and ICI viscosities, gloss, hiding power, and color characteristics. The paint films were also characterized by LVSEM–EDS, AFM, and profilometry. The most significant difference between a paint based on recycled pigments and a paint based on virgin pigments was the agglomeration of pigment particles which gave a reduction in gloss and a rougher surface of the dried paint film based on recycled pigment, and it could be concluded that the recycled pigment could not be used without accepting a small decrease in paint quality. This points toward two main directions: (1) the use of recycled pigment in applications with less demand on surface finish and gloss, such as ceiling paints, and (2) that further work on formulation should be carried out with the recycled pigment as for any other new pigment introduced in a paint formulation to optimize its performance. © 2018, The Author(s).

  • 23.
    Karlsson, Stefan
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Österlund, Lars
    Uppsala university, Sweden.
    Niklasson, Gunnar
    Uppsala university, Sweden.
    Granqvist, Claes-Göran
    Uppsala university, Sweden.
    Järn, Mikael
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Eriksson, Jerry
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Welinder, Jan
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Försth, Michael
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. Luleå tekniska universitet, Sweden.
    Ludvigsson, Mikael
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    “Transparent Intelligence” for Sustainable Development2018Conference paper (Refereed)
    Abstract [en]

    Transparent materials are essential in everyone’s life. They enable daylight to reach the interior of buildings, thereby contributing to both our physical and mental well-being; they are the primary component for communication via optical fibers and a key component in electronic devices such as protective cover and/or dielectric material; and they enable clean energy production through solar panels or algae reactors by acting as protective and light transmitting barriers. Adding functions to transparent materials in an intelligent way creates further opportunities to use and enhance the beneficial impacts of transparency. The concept Transparent Intelligence covers transparent materials and products with integral intelligent functions – passive, active or interactive. By using Transparent Intelligence it is possible to embrace many of the societal challenges that we are facing today. The concept can be divided into five broad industrial sectors: Built Environment, Information and Communication Technologies (ICT), Solar Energy, Mobility, and Materials. A perspective on how Transparent Intelligence can improve the sustainable development of our world will be presented, using examples of electrochromic windows for energy-efficient buildings, photocatalytic coatings for improved indoor air quality, transparent conductive coatings for antennas, bandpass filters for mobile phone indoor coverage, UV down-converting components for efficient solar energy, hygienic surfaces for infection mitigation on electronic devices, printed electronics for sustainable glass packaging, and IR-reflecting coatings for fire safety.

  • 24.
    Kharitonov, D. S.
    et al.
    Belarusian State Technological University, Belarus ; KTH Royal Institute of Technology, Sweden.
    Dobryden’, I. B.
    KTH Royal Institute of Technology, Sweden.
    Sefer, B.
    Luleå University of Technology, Sweden.
    Zharskii, I. M.
    Belarusian State Technological University, Belarus.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Kurilo, I. I.
    Belarusian State Technological University, Belarus.
    Corrosion of AD31 (AA6063) Alloy in Chloride-Containing Solutions2018In: Protection of Metals and Physical Chemistry of Surfaces, ISSN 2070-2051, Vol. 54, no 2, p. 291-300Article in journal (Refereed)
    Abstract [en]

    Corrosion of AD31 (AA6063) alloy in neutral 0.05 M NaCl solutions is investigated via scanningprobe microscopy, linear-sweep voltammetry, and electrochemical-impedance spectroscopy. Al−Fe−Si−Mg intermetallic particles are determined to prevail in the structure of alloy and act as local cathodes. Intermodulation electrostatic-force-microscopy imaging shows that their Volta potential differs by 570 mV from that of the host aluminum matrix, making the alloy prone to localized corrosion. We show that the corrosion of alloy in the studied electrolyte mainly develops locally and results in pitting, with charge transfer being the limiting stage of the process. A mechanism of corrosion of the AD31 (AA6063) alloy in neutral chloride-containing solutions is proposed.

  • 25.
    Kharitonov, Dmitry S.
    et al.
    KTH Royal Institute of Technology, Sweden ; Belarusian State Technological University, Belarus.
    Örnek, Cem
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB. KTH Royal Institute of Technology, Sweden.
    Claesson, Per M
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Zharskii, Ivan M.
    Belarusian State Technological University, Belarus.
    Kurilo, Irina I.
    Belarusian State Technological University, Belarus.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Corrosion Inhibition of Aluminum Alloy AA6063-T5 by Vanadates: Microstructure Characterization and Corrosion Analysis2018In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 5, no 3, p. C116-C126Article in journal (Refereed)
    Abstract [en]

    Corrosion inhibition of aluminum alloy AA6063-T5 by vanadates (NaVO3) in 0.05 M NaCl solution has been investigated by electrochemical and weight loss measurements, and associated with microstructure and Volta potential data. X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analyses confirmed the presence of micrometer-sized Fe-rich Al4.01MnSi0.74, Al1.69Mg4Zn2.31, and FeAl3intermetallic phases (IMPs) and nanometer-sized CuAl2, ZnAl2, and Mg2Si precipitates in the microstructure. Scanning Kelvin probe force microscopy measurements showed Volta potential differences of up to 600 mV between the microstructure constituents indicating a high susceptibility to micro-galvanic corrosion, with interphase boundary regions exhibiting the highest propensity to corrosion. Most IMPs had cathodic character whereas some nanometer-sized Mg-rich particles exhibited anodic nature, with large Volta potential gradients within interphase regions of large cathodic particles. Electrochemical potentiodynamic polarization measurements indicated that the vanadates provided mixed corrosion inhibition effects, mitigating both oxygen reduction, occurring on cathodic IMPs, and anodic metal dissolution reaction, occurring on anodic sites, such as Mg2Si and interphase boundary regions. Electrochemical measurements indicated that the sodium metavanadate inhibitor blocks active metal dissolution, giving high inhibition efficiency (>95%) during the initial exposure, whereas long-term weight loss measurements showed that the efficacy decreases after prolonged exposure.

  • 26.
    Koppolu, Rajesh
    et al.
    Åbo Akademi University, Finland.
    Abitbol, Tiffany
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Kumar, Vinay
    Åbo Akademi University, Finland.
    Jaiswal, Aayush K.
    Åbo Akademi University, Finland.
    Swerin, Agne
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Toivakka, Martti
    Åbo Akademi University, Finland; VTT Technical Research Center of Finland Ltd, Finland.
    Continuous roll-to-roll coating of cellulose nanocrystals onto paperboard2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 10, p. 6055-6069Article in journal (Refereed)
    Abstract [en]

    There is an increased interest in the use of cellulose nanocrystal (CNC) films and coatings for a range of functional applications in the fields of material science, biomedical engineering, and pharmaceutical sciences. Most of these applications have been demonstrated on films and coatings produced using laboratory-scale batch processes, such as solvent casting, dip coating, or spin coating. For successful coating application of CNC suspensions using a high throughput process, several challenges need to be addressed: relatively high viscosity at low solids content, coating brittleness, and potentially poor adhesion to the substrate. This work aims to address these problems. The impact of plasticizer on suspension rheology, coating adhesion, and barrier properties was quantified, and the effect of different pre-coatings on the wettability and adhesion of CNC coatings to paperboard substrates was explored. CNC suspensions were coated onto pre-coated paperboard in a roll-to-roll process using a custom-built slot die. The addition of sorbitol reduced the brittleness of the CNC coatings, and a thin cationic starch pre-coating improved their adhesion to the paperboard. The final coat weight, dry coating thickness, and coating line speed were varied between 1–11 g/m2, 900 nm–7 µm, and 2.5–10 m/min, respectively. The barrier properties, adhesive strength, coating coverage, and smoothness of the CNC coatings were characterized. SEM images show full coating coverage at coat weights as low as 1.5 g/m2. With sorbitol as plasticizer and at coat weights above 3.5 g/m2, heptane vapor and water vapor transmission rates were reduced by as much as 99% and 75% respectively. Compared to other film casting techniques, the process employed in this work deposits a relatively thick coating in significantly less time, and may therefore pave the way toward various functional applications based on CNCs.

  • 27.
    Lavelle, E
    et al.
    Trinity College, Ireland.
    Moran, L
    Trinity College, Ireland.
    Andersson, Mats
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    The impact of chitosan acetylation pattern on inflammation and toxicity2018In: The 14th International Chitin and Chitosan Conference (14th ICCC): 12th Asia‐Pacific Chitin and Chitosan Symposium (12th APCCS), 2018Conference paper (Other academic)
    Abstract [en]

    The inherent properties of chitosan, being nontoxic, biodegradable and antimicrobial have attracted many scientists developing products for humans use in the fields of biomaterials and pharmaceuticals. Examples of such uses are as a carrier for vaccines and drugs, and as a scaffold for living cells. Many projects have failed due to unwanted side reactions, failure to meet technical specifications or to comply with the regulatory standards set by the medical authorities. There are several contradictions in the literature regarding the role chitosan plays in inducing inflammatory reactions. One common view is that chitosan possess anti-inflammatory properties but there are also examples indicating the opposite, that chitosan promotes inflammation. The origin of an inflammatory reaction is often difficult to tell, is it an effect of the chitosan itself or could it be attributed to remaining impurities in it, like endotoxins or protein residues? Purity and consistency in manufacturing are certainly two issues that need to be overcome. The role of chitosan in inflammatory processes is still not fully understood and further experiments with well characterized preparations are needed to reveal the underlying mechanisms.

    Technically chitosan can be divided in two categories based on their acetylation pattern, heterogeneously and homogeneously deacetylated chitosans.  Their different acetylation pattern follows on the processes used for their manufacturing. This means that depending on the manufacturing process two chitosans could have the same degree of deacetylation and molecular weight, be indistinguishable by 1H-NMR and still be structurally different.

    With a set of well characterized samples, representing heterogeneously and homogeneously deacetylated chitosans, we have investigated the effects of six different chitosans with respect to their impact on different inflammatory markers and cell toxicity. Our results show large differences between the two categories. The homogenously deacetylated chitosans are all poor inducers of inflammatory reactions and show very low toxicity whereas their heterogeneously deacetyleted cousins are significantly more toxic and seems to promote inflammatory reactions.

  • 28.
    Lee, Jookyeong
    et al.
    Sungkyunkwan University, Republic of Korea .
    Choi, Eun Jung
    Sungkyunkwan University, Republic of Korea .
    Varga, Imre
    Eötvös Loránd University, Hungary.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Yun, Sang-Ho
    Inha University, Republic of Korea.
    Song, Changsik
    Sungkyunkwan University, Republic of Korea .
    Terpyridine-functionalized stimuli-responsive microgels and their assembly through metal-ligand interactions2018In: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 9, no 8, p. 1032-1039Article in journal (Refereed)
    Abstract [en]

    We developed a terpyridine-functionalized microgel (tpy-mG) for its supramolecular assembly. Tpy-mG was synthesized by amidation between 3-(4-([2,2′:6′,2′′-terpyridin]-4′-yl)phenoxy)propan-1-amine and carboxylates of a thermo-responsive p(NIPAM-co-MAA) microgel (A-mG), which was synthesized by emulsion polymerization. After decorating terpyridine, its effects on the hydrodynamic radius, volume phase transition temperature (VPTT), and the colloidal stability of the microgel were investigated. Tpy-mG can be assembled reversibly with several metal ions (Ni2+, Fe2+, Co2+, or Zn2+), and interestingly the assembled tpy-mG-M2+ showed different rheological properties depending on the metal ion type; the weakly bound ions (Co2+, Zn2+) indicated fast dynamics for "inter-particular" exchange, resulting in much higher storage (G′) and loss (G′′) moduli. Photocatalysts such as Ru dyes can be easily introduced into tpy-mGvia metal-ligand interactions, and the photooxidation of benzylamine was tested. The free Ru dye showed almost the same conversions at 25 and 50 °C, whereas the assembled Ru-tpy-mG-Mg2+ displayed reduced conversion at 50 °C (&gt;VPTT). This is suggested to be due to the collapsed or "locked" structure around the photocatalytic center (Ru). Tpy-mG can be utilized as a good platform for developing responsive functional materials via reversible metal-ligand complexation.

  • 29.
    Lu, Xiaohu
    et al.
    Nynas AB, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Soenen, Hilde
    Nynas NV, Belgium.
    Andersson, Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Microstructures of bitumen observed by environmental scanning electron microscopy (ESEM) and chemical analysis using time-of-flight secondary ion mass spectrometry (TOF-SIMS)2018In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 229, p. 198-208Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to characterize structures induced on bitumen surfaces under analysis by environmental scanning electron microscopy (ESEM), and to examine possible contributing factors to the formation of their formation. Various bitumen samples are investigated, including soft and hard, as well as polymer modified bitumen. Chemical characterization is carried out by time-of-flight secondary ion mass spectrometry (TOF-SIMS), combined with principle component analysis (PCA). The study shows that, for soft bitumen, a tube pattern or worm structure is rapidly formed during ESEM analysis, but for hard bitumen, a longer exposure time is needed to develop a structure. The structures on the hard bitumen are also denser as compared to those on the soft bitumen. When sample specimens are deformed or stretched, the orientation of the created deformation is clearly reflected in the structures formed under ESEM, and for soft bitumen, the structure disappears overnight in vacuum but reappears with the same pattern upon repeated ESEM analysis. TOF-SIMS shows small but consistent chemical differences, indicating higher aliphatic and lower aromatic contents on the surface of the structured area compared to the unstructured area. Based on an estimated temperature increase on the bitumen surface due to the electron-beam irradiation, it is speculated that the ESEM-induced worm structure may be attributed to evaporation of volatiles, surface hardening and local expansion. In addition, under the electron-beam exposure, certain chemical reactions (e.g. breaking of chemical bonds, chain scission and crosslinking) may take place, possibly resulting in the observed chemical differences between the structured and unstructured areas.

  • 30.
    Lu, Xiaohu
    et al.
    Nynas AB, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Soenen, Hilde
    Nynas NV, Belgium.
    Blom, Johan
    Antwerp University, Belgium.
    Andersson, Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Visualization and chemical analysis of bitumen microstructures2019In: RILEM Bookseries, 2019, p. 168-173Conference paper (Refereed)
    Abstract [en]

    Microstructures of bitumen were investigated using atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM), and a chemical characterization was successfully carried out using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The bee structures were observed by AFM, for which a chemical explanation by wax was confirmed by the TOF-SIMS analysis. A tube pattern or worm structures were generated and visualized by ESEM on bitumen surfaces. Chemical differences between the structured and unstructured areas, as well as between different areas of the structure, were observed. A mechanism for the structure formation on bitumen surface during ESEM analysis is suggested.

  • 31.
    Lundin Johnson, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Noreland, David
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Gane, Patrick
    Omya International AG, Switzerland ; Aalto University, Finland.
    Schoelkopf, Joachim
    Omya International AG, Switzerland.
    Ridgway, Cathy
    Omya International AG, Switzerland.
    Millqvist Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Porous calcium carbonate as a carrier material to increase the dissolution rate of poorly soluble flavouring compounds2017In: Food & Function, ISSN 2042-6496, E-ISSN 2042-650X, Vol. 8, no 4, p. 1627-1640Article in journal (Refereed)
    Abstract [en]

    Two different food grade functionalised porous calcium carbonates (FCC), with different pore size and pore size distributions, were characterised and used as carrier materials to increase the dissolution rate of poorly soluble flavouring compounds in aqueous solution. The loading level was varied between 1.3% by weight (wt%) and 35 wt%, where the upper limit of 35 wt% was the total maximum loading capacity of flavouring compound in FCC based on the fraction of the total weight of FCC plus flavouring compound. Flavouring compounds (l-carvone, vanillin, and curcumin) were selected based on their difference in hydrophilicity and capacity to crystallise. Release kinetic studies revealed that all flavouring compounds showed an accelerated release when loaded in FCC compared to dissolution of the flavouring compound itself in aqueous medium. The amorphous state and/or surface enlargement of the flavouring compound inside or on FCC explains the faster release. The flavouring compounds capable of crystallising (vanillin and curcumin) were almost exclusively amorphous within the porous FCC material as determined by X-ray powder diffraction one week after loading and after storing the loaded FCC material for up to 9 months at room temperature. A small amount of crystalline vanillin and curcumin was detected in the FCC material with large pores and high flavouring compound loading (≥30 wt%). Additionally, two different loading strategies were evaluated, loading by dissolving the flavouring compound in acetone or loading by a hot melt method. Porosimetry data showed that the melt method was more efficient in filling the smallest pores (<100 nm). The main factor influencing the release rate appears to be the amorphous state of the flavouring compound and the increase in exposed surface area. The confinement in small pores prevents crystallisation of the flavouring compounds during storage, providing a stable amorphous form retaining high release rate also after storage.

  • 32.
    MacKenzie, Jordan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Söderberg, Daniel
    KTH Royal Institute of Technology, Sweden.
    Swerin, Agne
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Lundell, Fredrik
    KTH Royal Institute of Technology, Sweden.
    Turbulent stress measurements of fibre suspensions in a straight pipe2018In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 30, no 2, article id 025104Article in journal (Refereed)
    Abstract [en]

    The focus of the present work is an experimental study of the behaviour of semi-dilute, opaque fibre suspensions in fully developed cylindrical pipe flows. Measurements of the normal and turbulent shear stress components and the mean flow were acquired using phase-contrast magnetic resonance velocimetry. Two fibre types, namely, pulp fibre and nylon fibre, were considered in this work and are known to differ in elastic modulus. In total, three different mass concentrations and seven Reynolds numbers were tested to investigate the effects of fibre interactions during the transition from the plug flow to fully turbulent flow. It was found that in fully turbulent flows of nylon fibres, the normal, uzuz+, and shear, uzur+ (note that · is the temporal average, u is the fluctuating velocity, z is the axial or streamwise component, and r is the radial direction), turbulent stresses increased with Reynolds number regardless of the crowding number (a concentration measure). For pulp fibre, the turbulent stresses increased with Reynolds number when a fibre plug was present in the flow and were spatially similar in magnitude when no fibre plug was present. Pressure spectra revealed that the stiff, nylon fibre reduced the energy in the inertial-subrange with an increasing Reynolds and crowding number, whereas the less stiff pulp fibre effectively cuts the energy cascade prematurely when the network was fully dispersed.

  • 33.
    Malm, Lisa
    et al.
    Boliden Mineral, Sweden.
    Danielsson, Ann-Sofie
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Sand, Anders
    Luleå Technical University, Sweden.
    Rosenkranz, Jan
    Luleå Technical University, Sweden.
    Ymén, Ingvar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Application of Dynamic Vapor Sorption for evaluation of hydrophobicity in industrial-scale froth flotation2017In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444Article in journal (Refereed)
    Abstract [en]

    The particle surface properties are essential for understanding froth flotation, particularly for the evaluation of various chemical or reagent effects.Dynamic Vapor Sorption (DVS) is used in the pharmaceutical industry for the evaluation of surface properties and has to the knowledge of the authors not been used for applications in mineral processing. This paper describes an evaluation of industrial ore samples using DVS.Four samples (feed, CuPb concentrate, Cu concentrate and Pb concentrate) from each of the Cu - Pb flotation processes in the Boliden and Garpenberg concentrators, Sweden, were analyzed by DVS in order to investigate if this technique could be used to estimate differences in their hydrophilicity. The DVS measures the water uptake as a function of the relative humidity (%RH) at constant temperature.For both series of four samples, it was found that the DVS-data are in precise agreement with the flotation theory on hydrophobicity (indicated by differences in water uptake). The feed material, without any collectors, adsorbed more water compared to the CuPb bulk concentrate, which in turn adsorbed more water than the Cu concentrate. The lead concentrate on the other hand, which had been depressed by dichromate and should be more hydrophilic, showed a higher adsorbance of water than that of the CuPb concentrate.The repeated measurements of three sub samples from one of the ore samples gave a mean value and an estimated standard deviation of 0.13 ± 0.01%. This shows that the method gives highly reproducible results and that the differences between the samples had high significance. This also shows that the DVS method can serve as a useful complement to traditionally used contact angle or capillary absorption-based measurement methods, especially when screening for new flotation reagents on industrial ore samples.

  • 34.
    Moen, Ingrid
    et al.
    Oxy Solutions AS, Norway.
    Ugland, Hege
    Oxy Solutions AS, Norway.
    Strömberg, Niklas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sjöström, Eva
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Karlsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Bysell, Helena
    RISE - Research Institutes of Sweden.
    Amiry‐Moghaddam, Mahmood
    Oxy Solutions AS, Norway ; University of Oslo, Norway.
    Hagleröd, Camilla
    Oxy Solutions AS, Norway.
    Development of a novel in situ gelling skin dressing: Deliveringhigh levels of dissolved oxygen at pH 5.52018In: Health Sci Rep., article id e57Article in journal (Refereed)
    Abstract [en]

    Background and aims: Wound healing requires appropriate oxygen and pH levels.Oxygen therapy and pH‐modulating treatments have shown positive effects onwound healing. Thus, a dressing, which combines high levels of dissolved oxygen(DO) with the pH of intact skin, may improve wound healing. Our aims were to (1) formulatean in situ gelling dressing with high levels of DO and with the pH level of intactskin, (2) evaluate physical and chemical properties of the dressing, and (3) elucidatebasic effects of elevated levels of DO on human skin cells in vitro.Methods: A dressing was formulated with 15 to 16 wt% poloxamer 407, acetatebuffer, and oxygenated water. Stability of pH and DO, rheology, and shelf life wereanalysed. Furthermore, in vitro studies of the effect of increased levels of DO wereperformed.Results: An in situ gelling wound dressing, with a DO concentration rangingbetween 25 and 35 mg/L and a pH of 5.5, was formulated. The DO concentrationwas stable above 22 mg/L for at least 30 hours when applied on a surface at 35°Cand covered for directed diffusion into the intended wound area. At storage, thedressing had stable pH for 3 months and stable DO concentration over 30 mg/L for7 weeks. Increasing DO significantly enhanced intracellular ATP in human skin cells,without changing reactive oxygen species production, proliferation rate, or viability.Conclusion: The developed dressing may facilitate wound healing by deliveringcontrolled and stable oxygen levels, providing adjustable pH for optimized healing,and increasing intracellular ATP availability.

  • 35.
    Moran, Hannah B T
    et al.
    Trinity College Dublin, Ireland.
    Turley, Joanna L
    Trinity College Dublin, Ireland.
    Andersson, Mats
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Lavelle, Ed C
    Trinity College Dublin, Ireland.
    Immunomodulatory properties of chitosan polymers2018In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 184, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The introduction of vaccines is regarded as one of the most successful medical interventions to date. However, there is a clear need for the development of new vaccines for diseases which require the induction of a potent cellular immune response. Advancements in the field of vaccine research have resulted in a move away from the use of whole organisms and towards the use of subunit vaccines which consist of highly purified antigens with an improved safety profile. Adjuvants are immunostimulatory components that are included in subunit vaccine formulations to help direct and amplify adaptive immune responses. Chitosan is a cationic polysaccharide that has been examined in an adjuvant setting due to its biocompatible and biodegradable nature. The polysaccharide has been shown to have the capacity to induce Th1 cell responses following vaccination by injection or mucosal routes, supporting its application as an alternative to alum for vaccines that promote cell-mediated immunity. Here, we provide an overview of the physico-chemical properties of chitosan with a focus on the specific characteristics that dictate the type and scale of the immune responses induced. The potential to finely tailor chitosan polymers in order to direct specific types of immune responses can provide invaluable tools for the design of novel chitosan-based adjuvants and biomaterials.

  • 36.
    Mukherjee, Sourav P.
    et al.
    Karolinska Institutet, Sweden .
    Gliga, Anda R.
    Karolinska Institutet, Sweden .
    Lazzaretto, Beatrice
    Karolinska Institutet, Sweden .
    Brandner, Birgit
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Fielden, Matthew
    KTH Royal Institute of Technology, Sweden.
    Vogt, Carmen
    KTH Royal Institute of Technology, Sweden.
    Newman, Leon
    University of Manchester, UK.
    Rodrigues, Artur F.
    University of Manchester, UK.
    Shao, Wenting
    University of Pittsburgh, USA.
    Fournier, Philip M.
    University of Pittsburgh, USA.
    Toprak, Mohammet S.
    KTH Royal Institute of Technology, Sweden.
    Star, Alexander
    University of Pittsburgh, USA.
    Kostarelos, Kostas
    University of Manchester, UK.
    Bhattacharya, Kunel
    Karolinska Institutet, Sweden .
    Fadeel, Bengt
    Karolinska Institutet, Sweden .
    Graphene oxide is degraded by neutrophils and the degradation products are non-genotoxic2018In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 10, no 3, p. 1180-1188Article in journal (Refereed)
    Abstract [en]

    Neutrophils were previously shown to digest oxidized carbon nanotubes through a myeloperoxidase (MPO)-dependent mechanism, and graphene oxide (GO) was found to undergo degradation when incubated with purified MPO, but there are no studies to date showing degradation of GO by neutrophils. Here we produced endotoxin-free GO by a modified Hummers' method and asked whether primary human neutrophils stimulated to produce neutrophil extracellular traps or activated to undergo degranulation are capable of digesting GO. Biodegradation was assessed using a range of techniques including Raman spectroscopy, transmission electron microscopy, atomic force microscopy, and mass spectrometry. GO sheets of differing lateral dimensions were effectively degraded by neutrophils. As the degradation products could have toxicological implications, we also evaluated the impact of degraded GO on the bronchial epithelial cell line BEAS-2B. MPO-degraded GO was found to be non-cytotoxic and did not elicit any DNA damage. Taken together, these studies have shown that neutrophils can digest GO and that the biodegraded GO is non-toxic for human lung cells.

  • 37.
    Niemelä-Anttonen, Henna
    et al.
    Tampere University of Technology, Finland.
    Koivuluoto, Heli
    Tampere University of Technology, Finland.
    Tuominen, Mikko
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Teisala, Hannu
    Max Planck Institute for Polymer Research, Germany.
    Juuti, Paxton
    Tampere University of Technology, Finland.
    Haapanen, Janne
    Tampere University of Technology, Finland.
    Harra, Juha
    Tampere University of Technology, Finland.
    Stenroos, Christian
    Tampere University of Technology, Finland.
    Lahti, Johanna
    Tampere University of Technology, Finland.
    Kuusipalo, Jurkka
    Tampere University of Technology, Finland.
    Mäkelä, Jyrki M.
    Tampere University of Technology, Finland.
    Vuoristo, Petri
    Tampere University of Technology, Finland.
    Icephobicity of Slippery Liquid Infused Porous Surfaces under Multiple Freeze–Thaw and Ice Accretion–Detachment Cycles2018In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 5, no 20, article id 1800828Article in journal (Refereed)
    Abstract [en]

    Surface engineering can be used to prevent ice accumulation and adhesion in environments that deal with icing problems. One recent engineering approach, slippery liquid infused porous surfaces (SLIPS), comprises a smooth and slippery lubricating surface, where lubricant is trapped within the pores of a solid material to repel various substances, such as water and ice. However, it remains unclear whether the slippery surfaces retain their icephobic characteristics under the impact of supercooled water droplets or repeated freezing and melting cycles. Here, the icephobic properties of SLIPS are evaluated under multiple droplet freeze–thaw and ice accretion–detachment cycles and compared to hydrophobic and superhydrophobic surfaces. The experiments are designed to mimic real environmental conditions, thus, the icephobicity is investigated in icing wind tunnel, where ice accretion occurs through the impact of supercooled water droplets. The adhesion of ice remained extremely low, <10 kPa, which is four times lower than ice adhesion onto smooth fluoropolymer surfaces, even after repeated ice accretion–detachment cycles. Moreover, cyclic droplet freeze–thaw experiments provide insight into the effects of temperature cycling on SLIPS wettability, showing stable wetting performance. The results suggest liquid infused porous surfaces as a potential solution to icephobicity under challenging and variating environmental conditions.

  • 38.
    Niga, Petru
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Hansson-Mille, Petra M
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Swerin, Agne
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Claesson, Per M
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Schoelkopf, Joachim
    Omya International AG, Switzerland.
    Gane, Patrick A C
    Omya International AG, Switzerland ; Aalto University, Finland.
    Bergendal, Erik
    KTH Royal Institute of Technology, Sweden.
    Tummino, Andrea
    Institut Laue-Langevin, France ; Eötvös Loránd University, Hungary.
    Campbell, Richard A
    Institut Laue-Langevin, France.
    Johnson, C Magnus
    KTH Royal Institute of Technology, Sweden.
    Interactions between model cell membranes and the neuroactive drug propofol.2018In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 526, p. 230-243Article in journal (Refereed)
    Abstract [en]

    phospholipid, NR data reveal that propofol is located exclusively in the head group region, which is rationalized in the context of previous studies. The results imply a non-homogeneous distribution of propofol in the plane of real cell membranes, which is an inference that requires urgent testing and may help to explain why such low concentration of the drug are required to induce general anaesthesia.

  • 39.
    Nordenström, Malin
    et al.
    KTH, Royal Institute of Technology, Sweden ; WWSC Wallenberg Wood Science Center, Sweden.
    Riazanova, Anastasia V
    KTH, Royal Institute of Technology, Sweden ; WWSC Wallenberg Wood Science Center, Sweden.
    Järn, Mikael
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Paulraj, Thomas
    KTH, Royal Institute of Technology, Sweden ; WWSC Wallenberg Wood Science Center, Sweden.
    Turner, Charlotta
    Lund University, Sweden.
    Ström, Valter
    KTH, Royal Institute of Technology, Sweden.
    Olsson, Richard T
    KTH, Royal Institute of Technology, Sweden ; WWSC Wallenberg Wood Science Center, Sweden.
    Svagan, Anna J
    KTH, Royal Institute of Technology, Sweden ; WWSC Wallenberg Wood Science Center, Sweden.
    Superamphiphobic coatings based on liquid-core microcapsules with engineered capsule walls and functionality.2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, no 1, article id 3647Article in journal (Refereed)
    Abstract [en]

    Microcapsules with specific functional properties, related to the capsule wall and core, are highly desired in a number of applications. In this study, hybrid cellulose microcapsules (1.2 ± 0.4 µm in diameter) were prepared by nanoengineering the outer walls of precursor capsules. Depending on the preparation route, capsules with different surface roughness (raspberry or broccoli-like), and thereby different wetting properties, could be obtained. The tunable surface roughness was achieved as a result of the chemical and structural properties of the outer wall of a precursor capsule, which combined with a new processing route allowed in-situ formation of silica nanoparticles (30-40 nm or 70 nm in diameter). By coating glass slides with "broccoli-like" microcapsules (30-40 nm silica nanoparticles), static contact angles above 150° and roll-off angles below 6° were obtained for both water and low surface-tension oil (hexadecane), rendering the substrate superamphiphobic. As a comparison, coatings from raspberry-like capsules were only strongly oleophobic and hydrophobic. The liquid-core of the capsules opens great opportunities to incorporate different functionalities and here hydrophobic superparamagnetic nanoparticles (SPIONs) were encapsulated. As a result, magnetic broccoli-like microcapsules formed an excellent superamphiphobic coating-layer on a curved geometry by simply applying an external magnetic field.

  • 40.
    Pace, Hudson
    et al.
    Chalmers University of Technology, Sweden.
    Hannestad, Jonas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Armonious, Antonius
    Chalmers University of Technology, Sweden.
    Adamo, Marco
    Institute Laue-Langevin, France ; Imperial College London, UK.
    Agnarsson, Bjorn
    Chalmers University of Technology, Sweden.
    Gunnarsson, Anders
    AstraZeneca, Sweden.
    Micciulla, Samantha
    Institute Laue-Langevin, France ; Max Planck Institute of Colloids and Interfaces, Germany.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Gerelli, Yuri
    Institute Laue-Langevin, France.
    Höök, Fredrik
    Chalmers University of Technology, Sweden.
    Structure and Composition of Native Membrane Derived Polymer-Supported Lipid Bilayers2018In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 90, no 21, p. 13065-13072Article in journal (Refereed)
    Abstract [en]

    Over the last two decades, supported lipid bilayers (SLBs) have been extensively used as model systems to study cell membrane structure and function. While SLBs have been traditionally produced from simple lipid mixtures, there has been a recent surge in compositional complexity to better mimic cellular membranes and thereby bridge the gap between classic biophysical approaches and cell experiments. To this end, native cellular membrane derived SLBs (nSLBs) have emerged as a new category of SLBs. As a new type of biomimetic material, an analytical workflow must be designed to characterize its molecular composition and structure. Herein, we demonstrate how a combination of fluorescence microscopy, neutron reflectometry, and secondary ion mass spectrometry offers new insights on structure, composition, and quality of nSLB systems formed using so-called hybrid vesicles, which are a mixture of native membrane material and synthetic lipids. With this approach, we demonstrate that the nSLB formed a continuous structure with complete mixing of the synthetic and native membrane components and a molecular stoichiometry that essentially mirrors that of the hybrid vesicles. Furthermore, structural investigation of the nSLB revealed that PEGylated lipids do not significantly thicken the hydration layer between the bilayer and substrate when on silicon substrates; however, nSLBs do have more topology than their simpler, purely synthetic counterparts. Beyond new insights regarding the structure and composition of nSLB systems, this work also serves to guide future researchers in producing and characterizing nSLBs from their cellular membrane of choice.

  • 41.
    Persson, Karin
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Magner, Jörgen
    IVL, Sweden.
    Royen, Hugo
    IVL, Sweden.
    Filipsson, Staffan
    IVL, Sweden.
    A Photocatalytic Membrane For Treatment of Pharmaceuticals in Wastewater2017Report (Other academic)
    Abstract [en]

    Toxic organics, pharmaceuticals and antibiotics are currently only partially or not at all removed from wastewater, as today’s wastewater treatment will only partly degrade those substances. Therefore, those substances will be found in the effluent from wastewater treatment plants and this can be a threat to both human health and aquatic species.

    Photocatalytic membranes show great promise as a method to combat the challenge of toxic organics in wastewater. The novel photocatalytic membrane developed in the project was shown to photocatalytically decompose organic compounds such as pharmaceutical residues and dyes in both tap water and treated effluent from a membrane bioreactor (MBR) wastewater treatment process. Several parameters affecting the affinity of the pharmaceuticals to the membrane surface, such as the hydrophobicity and pKa of the pharmaceuticals and the pH of the water, were shown to affect the efficacy of the removal.

    Finally, when irradiated with UV light the photocatalytic membrane showed promise of keeping high flux and reducing downtime by lengthening the cleaning cycle.

  • 42.
    Pradhan, Sulena
    et al.
    KTH Royal Institute of Technology, Sweden.
    Hedberg, Jonas
    KTH Royal Institute of Technology, Sweden.
    Rosenqvist, Jörgen
    University of Gothenburg, Sweden.
    Jonsson, Caroline M.
    University of Gothenburg, Sweden.
    Wold, Susanna
    KTH Royal Institute of Technology, Sweden.
    Blomberg, Eva
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Wallinder, Inger O.
    KTH Royal Institute of Technology, Sweden.
    Influence of humic acid and dihydroxy benzoic acid on the agglomeration, adsorption, sedimentation and dissolution of copper, manganese, aluminum and silica nanoparticles-A tentative exposure scenario2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 2, article id e0192553Article in journal (Refereed)
    Abstract [en]

    This work focuses on kinetic aspects of stability, mobility, and dissolution of bare Cu, Al and Mn, and SiO2 NPs in synthetic freshwater (FW) with and without the presence of natural organic matter (NOM). This includes elucidation of particle and surface interactions, metal dissolution kinetics, and speciation predictions of released metals in solution. Dihydroxy benzoic acid (DHBA) and humic acid adsorbed rapidly on all metal NPs (&lt;1 min) via multiple surface coordinations, followed in general by rapid agglomeration and concomitant sedimentation for a large fraction of the particles. In contrast, NOM did not induce agglomeration of the SiO2 NPs during the test duration (21 days). DHBA in concentrations of 0.1 and 1 mM was unable to stabilize the metal NPs for time periods longer than 6 h, whereas humic acid, at certain concentrations (20 mg/L) was more efficient (&gt;24 h). The presence of NOM increased the amount of released metals into solution, in particular for Al and Cu, whereas the effect for Mn was minor. At least 10% of the particle mass was dissolved within 24 h and remained in solution for the metal NPs in the presence of NOM. Speciation modeling revealed that released Al and Cu predominantly formed complexes with NOM, whereas less complexation was seen for Mn. The results imply that potentially dispersed NPs of Cu, Al and Mn readily dissolve or sediment close to the source in freshwater of low salinity, whereas SiO2 NPs are more stable and therefore more mobile in solution. © 2018 Pradhan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

  • 43.
    Ren, Yansong
    et al.
    KTH Royal Institute of Technology, Sweden.
    Svensson, Per H.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Ramström, Olof
    University of Massachusetts Lowell, US ; KTH Royal Institute of Technology, Sweden.
    A Multicontrolled Enamine Configurational Switch Undergoing Dynamic Constitutional Exchange2018In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 57, no 21, p. 6256-6260Article in journal (Refereed)
    Abstract [en]

    A multiresponsive enamine-based molecular switch is presented, in which forward/backward configurational rotation around the C=C bond could be precisely controlled by the addition of an acid/base or metal ions. Fluorescence turn-on/off effects and large Stokes shifts were observed while regulating the switching process with CuII. The enamine functionality furthermore enabled double dynamic regimes, in which configurational switching could operate in conjunction with constitutional enamine exchange of the rotor part. This behavior was used to construct a prototypical dynamic covalent switch system through enamine exchange with primary amines. The dynamic exchange process could be readily turned on/off by regulating the switch status with pH.

  • 44.
    Reverdy, Charlene
    et al.
    Univ. Grenoble Alpes, France.
    Belgacem, Naceur
    Univ. Grenoble Alpes, France.
    Moghaddam, Maziar Sedigh
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Sundin, Mikael
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Swerin, Agne
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Bras, Julien
    Univ. Grenoble Alpes, France ; Institut Universitaire de France, France.
    One-step superhydrophobic coating using hydrophobized cellulose nanofibrils2018In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 544, p. 152-158Article in journal (Refereed)
    Abstract [en]

    Superhydrophobic surfaces have high potential in self-cleaning and anti-fouling applications. We developed a one-step superhydrophobic coating formulation containing sodium oleate (NaOl), hydrophobized precipitated calcium carbonate and biobased cellulose nanofibrils (CNFs) hydrophobized with either alkyl ketene dimer (AKD) or amino propyl trimethoxy silane (APMS) as a binder to fix and distribute the particles. Coatings were made on paperboard and the wetting behavior of the surface was assessed. Static, advancing and receding contact angles with water as well as roll-off and water shedding angle were compared to coatings made with styrene butadiene latex as binder instead of CNFs. Modifications with alkyl ketene dimer showed most promising results for a viable process in achieving superhydrophobic paperboard but required reformulation of the coating with optimized and reduced amount of NaOl to avoid surfactant-induced wetting via excess NaOl. A static water contact angle of 150° was reached for the CNF-AKD. The use of CNFs enables the improvement of coating quality avoiding cracking with the use of nanocellulose as a renewable binder.

  • 45.
    Rinwa, Vihbu
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Schipper, Nicolaas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Bohlin, Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Warpman Berglund, Ulrika
    KI Karolinska Institute, Sweden.
    Scobie, Martin
    KI Karolinska Institute, Sweden.
    Helleday, Thomas
    KI Karolinska Institute, Sweden.
    Effect of chloride ion on solubility and dissolution of a basic drug and salt form for oral delivery2018Conference paper (Other academic)
    Abstract [en]

    Introduction:

    Chloride ions are the predominant anionic counter-ion present in vivo (intestine/ jejunum: 0.13M and stomach: 0.10M), significantly effecting solubility and dissolution of drugs for oral absorption1. Our group has recently discovered a novel small molecule, with good permeability but low aqueous solubility potentially limiting exposure after oral administration. It is a basic compound (pKa- 6-7) and provides opportunities to develop salt exploiting different counter-ions. Solubility is not only dependent on the ionization of the weak acid or weak base itself but also on the solubility of the counter ion pairs. Counter ion exchanges between salt forms or formation of hydrates is well known to occur in the gastrointestinal environment. If this happens, then formation of less soluble species can lead to in vivo precipitation of the drug.

  • 46.
    Safdari, Majid
    et al.
    KTH Royal Institute of Technology, Sweden .
    Phuyal, Dibya
    Uppsala Univiversity, Sweden.
    Philippe, Bertrand
    Uppsala Univiversity, Sweden.
    Svensson, Per H
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden .
    Butorin, Sergei M
    Uppsala Univiveristy, Sweden.
    Kvashnina, Kristina O
    ESRF-The European Synchrotron, France ; Institute of Resource Ecology, Germany.
    Rensmo, Håkan
    Uppsala University, Sweden.
    Kloo, Lars
    KTH Royal Institute of Technology, Sweden .
    Gardner, James M
    KTH Royal Institute of Technology, Sweden .
    Impact of synthetic routes on the structural and physical properties of butyl-1,4-diammonium lead iodide semiconductors2017In: Journals of materials chemistry AArticle in journal (Refereed)
    Abstract [en]

     We report the significant role of synthetic routes and the importance of     solvents in the synthesis of org.-inorg. lead iodide materials.  Through     one route, the intercalation of DMF in the crystal structure was obsd.     leading to a one--dimensional (1D) [NH3(CH2)4NH3]Pb2I6 structure of the     product.  This product was compared with the two-dimensional (2D)     [NH3(CH2)4NH3]PbI4 recovered from aq. solvent based synthesis with the     same precursors.  UV-visible absorption spectroscopy showed a red-shift of     0.1 eV for the band gap of the 1D network in relation to the 2D system.     This shift primarily originates from a shift in the valence band edge as     detd. from photoelectron- and X-ray spectroscopy results.  These findings     also suggest the iodide 5p orbital as the principal component in the d. of     states in the valence band edge.  Single crystal data show a change in the     local coordination around iodide, while in both materials, lead atoms are     surrounded by iodide atoms in octahedral units.  The cond. of the     one-dimensional material ([NH3(CH2)4NH3]Pb2I6) was 50% of the     two-dimensional material ([NH3(CH2)4NH3]PbI4).  The fabricated solar cells     reflect these changes in the chem. and electronic structure of both     materials, although the total light conversion efficiencies of solar cells based on both products were similar.

  • 47.
    Shah, Faiz U
    et al.
    Luleå University of Technology, Sweden.
    Holmgren, Allan
    Luleå University of Technology, Sweden.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Glavatskih, Sergei
    Ghent University, Belgium.
    Antzutkin, Oleg
    Luleå University of Technology, Sweden ; University of Warwick, UK.
    Interfacial Behavior of Orthoborate Ionic Liquids at Inorganic Oxide Surfaces Probed by NMR, IR, and Raman Spectroscopy2018In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 34, p. 19687-19698Article in journal (Refereed)
    Abstract [en]

    Absorption modes and the reactivity of nonhalogenated ionic liquids (ILs) at inorganic oxide surfaces of γ-Al2O3, MgO, and SiO2 particles were characterized using multinuclear (11B, 31P, and 29Si) solid-state magic-angle-spinning NMR, FTIR, and Raman spectroscopy. ILs are composed of the trihexyl(tetradecyl)phosphonium cation, [P6,6,6,14]+, and bis(mandelato)borate, [BMB]-, or bis(salicylato)borate, [BScB]-, anions. Spectroscopic measurements were performed on room-temperature (298 K) samples and samples exposed to 15 h at 373 K. The single-pulse 11B NMR data of heated [P6,6,6,14][BMB] mixed with the inorganic oxides showed a significant change in the spectra of the anion for all three oxides. In contrast, no such spectral changes were detected for heated [P6,6,6,14][BScB] mixed with the inorganic oxides. 31P MAS NMR data for the IL/metal oxide systems revealed interactions between [P6,6,6,14]+ and the surfaces of oxides. A significant intensity of 31P CP-MAS NMR signals indicated a low mobility of cations in these systems. The existence of strongly adhered surface layers of ILs on SiO2 particles was also confirmed by 1H-29Si CP-MAS NMR spectroscopy. FTIR and Raman spectroscopic data revealed strong interactions between the anions and the inorganic surfaces, and there is a strong correlation with the data obtained from NMR spectroscopy. Although their chemical structures are rather similar, the [BScB]- anion is more stable than the [BMB]- anion at the inorganic oxide surfaces.

  • 48.
    Sjövall, Peter
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Skedung, Lisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Gregoire, Sébastien
    L’OREAL Research and Innovation, France.
    Biganska, Olga
    L’OREAL Research and Innovation, France.
    Clément, Franck
    L’OREAL Research and Innovation, France.
    Luengo, Gustavo S
    L’OREAL Research and Innovation, France.
    Imaging the distribution of skin lipids and topically applied compounds in human skin using mass spectrometry.2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, no 1, article id 16683Article in journal (Refereed)
    Abstract [en]

    The barrier functions of skin against water loss, microbial invasion and penetration of xenobiotics rely, in part, on the spatial distribution of the biomolecular constituents in the skin structure, particularly its horny layer (stratum corneum). However, all skin layers are important to describe normal and dysfunctional skin conditions, and to develop adapted therapies or skin care products. In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) combined with scanning electron microscopy (SEM) was used to image the spatial distribution of a variety of molecular species, from stratum corneum down to dermis, in cross-section samples of human abdominal skin. The results demonstrate the expected localization of ceramide and saturated long-chain fatty acids in stratum corneum (SC) and cholesterol sulfate in the upper part of the viable epidermis. The localization of exogenous compounds is demonstrated by the detection and imaging of carvacrol (a constituent of oregano or thyme essential oil) and ceramide, after topical application onto ex vivo human skin. Carvacrol showed pronounced accumulation to triglyceride-containing structures in the deeper parts of dermis. In contrast, the exogenous ceramide was found to be localized in SC. Furthermore, the complementary character of this approach with classical ex vivo skin absorption analysis methods is demonstrated.

  • 49.
    Summerton, Emily
    et al.
    University of Birmingham, UK.
    Hollamby, Martin J
    University of Keele, UK.
    Zimbitas, Georgina
    University of Birmingham, UK.
    Snow, Tim
    Diamond Light Source, UK.
    Smith, Andrew J
    Diamond Light Source, UK.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Bettiol, Jeanluc
    Procter and Gamble Brussels Innovation Center, Belgium.
    Jones, Christopher
    Procter and Gamble Brussels Innovation Center, Belgium.
    Britton, Melanie M
    University of Birmingham, UK.
    Bakalis, Serafim
    University of Birmingham, UK ; University of Nottingham, UK.
    The impact of N,N-dimethyldodecylamine N-oxide (DDAO) concentration on the crystallisation of sodium dodecyl sulfate (SDS) systems and the resulting changes to crystal structure, shape and the kinetics of crystal growth.2018In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 527, p. 260-266, article id S0021-9797(18)30579-4Article in journal (Refereed)
    Abstract [en]

    HYPOTHESIS: At low temperatures stability issues arise in commercial detergent products when surfactant crystallisation occurs, a process which is not currently well-understood. An understanding of the phase transition can be obtained using a simple binary SDS (sodium dodecyl sulfate) + DDAO (N,N-dimethyldodecylamine N-oxide) aqueous system. It expected that the crystallisation temperature of an SDS system can be lowered with addition of DDAO, thus providing a route to improve detergent stability.

    EXPERIMENTS: Detergent systems are typically comprised of anionic surfactants, non-ionic surfactants and water. This study explores the crystallisation of a three component system consisting of sodium dodecyl sulfate (SDS), N,N-dimethyldodecylamine N-oxide (DDAO), and water using wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC) and confocal Raman microscopy.

    FINDINGS: O, formed whereas for mixed SDS + DDAO systems no such structure was detected during crystallisation.

  • 50.
    Valente, Filippo
    et al.
    University of Padua, Italy.
    Bysell, Helena
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Simoni, Edi
    University of Padua, Italy.
    Boge, Lukas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Eriksson, Mimmi
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Martini, Alessandro
    University of Padua, Italy.
    Astolfi, Laura
    University of Padua, Italy.
    Evaluation of toxicity of glycerol monooleate nanoparticles on PC12 cell line.2018In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 539, no 1-2, p. 23-30, article id S0378-5173(18)30054-1Article in journal (Refereed)
    Abstract [en]

    An innovative approach to improve drug delivery is the use of glycerol monooleate nanoparticles. Numerous studies describe their high versatility, low toxicity and ability to carry relatively high loads of conjugated compounds including scarcely soluble ones, providing sustained drug release and increasing drug diffusion and half-life. Despite a growing interest in their potential use for therapeutic applications, there are surprisingly few literature data concerning the toxic effects of these nanoparticles at high concentrations in vitro and in vivo, and their effects on cell metabolism. We produced and characterized from a physical-chemical point of view glycerol monooleate nanoparticles and tested them on the PC12 cell line, a rat model of neuronal differentiation. The toxicity of these nanoparticles was evaluated by molecular methods on cell viability, cell cycle, nanoparticle uptake and induction of apoptosis. The results showed that glycerol monooleate nanoparticles up to 100 μg/mL had no toxic effects on PC12 cells, did not induce significant changes in the cell cycle nor cause apoptosis. The nanoparticles entered PC12 cells 8 h after treatment, successfully delivering the conjugate compound inside cells. Overall, glycerol monooleate nanoparticles did not exhibit significant toxicity on PC12 cell line in concentrations up to 100 µg/mL, supporting their therapeutic use as drug delivery systems.

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