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  • 1.
    An, Junxue
    et al.
    KTH Royal Institute of Technology, Sweden.
    Liu, Xiaoyan
    KTH Royal Institute of Technology, Sweden.
    Dedinaite, Andra
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Korchagina, Evgeniya
    University of Montreal, Canada.
    Winnik, Francoise M.
    University of Montreal, Canada; National Institute for Materials Science, Japan; University of Helsinki, Finland.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Dedinaite, Andra
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Effect of solvent quality and chain density on normal and frictional forces between electrostatically anchored thermoresponsive diblock copolymer layers2017Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 487, s. 88-96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Equilibration in adsorbing polymer systems can be very slow, leading to different physical properties at a given condition depending on the pathway that was used to reach this state. Here we explore this phenomenon using a diblock copolymer consisting of a cationic anchor block and a thermoresponsive block of poly(2-isopropyl-2-oxazoline), PIPOZ. We find that at a given temperature different polymer chain densities at the silica surface are achieved depending on the previous temperature history. We explore how this affects surface and friction forces between such layers using the atomic force microscope colloidal probe technique. The surface forces are purely repulsive at temperatures <40 °C. A local force minimum at short separation develops at 40 °C and a strong attraction due to capillary condensation of a polymer-rich phase is observed close to the bulk phase separation temperature. The friction forces decrease in the cooling stage due to rehydration of the PIPOZ chain. A consequence of the adsorption hysteresis is that the friction forces measured at 25 °C are significantly lower after exposure to a temperature of 40 °C than prior to heating, which is due to higher polymer chain density on the surface after heating.

  • 2.
    Assenhöj, Maria
    et al.
    Linköping University, Sweden.
    Eriksson, Peter
    Linköping University, Sweden.
    Dönnes, Pierre
    SciCross AB, Sweden.
    Ljunggren, Stefan
    Linköping University, Sweden.
    Marcusson-Ståhl, Maritha
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Du Rietz, Anna
    Linköping University, Sweden.
    Uvdal, Kajsa
    Linköping University, Sweden.
    Karlsson, Hanna
    Linköping University, Sweden.
    Cederbrant, Karin
    RISE Research Institutes of Sweden.
    Protein interaction, monocyte toxicity and immunogenic properties of cerium oxide crystals with 5% or 14% gadolinium, cobalt oxide and iron oxide nanoparticles–an interdisciplinary approach2021Ingår i: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 15, nr 8, s. 1035-1038Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metal oxide nanoparticles are widely used in both consumer products and medical applications, but the knowledge regarding exposure-related health effects is limited. However, it is challenging to investigate nanoparticle interaction processes with biological systems. The overall aim of this project was to improve the possibility to predict exposure-related health effects of metal oxide nanoparticles through interdisciplinary collaboration by combining workflows from the pharmaceutical industry, nanomaterial sciences, and occupational medicine. Specific aims were to investigate nanoparticle-protein interactions and possible adverse immune reactions. Four different metal oxide nanoparticles; CeOx nanocrystals with 5% or 14% Gd, Co3O4, and Fe2O3, were characterized by dynamic light scattering and high-resolution transmission electron microscopy. Nanoparticle-binding proteins were identified and screened for HLA-binding peptides in silico. Monocyte interaction with nanoparticle–protein complexes was assessed in vitro. Herein, for the first time, immunogenic properties of nanoparticle-binding proteins have been characterized. The present study indicates that especially Co3O4-protein complexes can induce both ‘danger signals’, verified by the production of inflammatory cytokines and simultaneously bind autologous proteins, which can be presented as immunogenic epitopes by MHC class II. The clinical relevance of these findings should be further evaluated to investigate the role of metal oxide nanoparticles in the development of autoimmune disease. The general workflow identified experimental difficulties, such as nanoparticle aggregate formation and a lack of protein-free buffers suitable for particle characterization, protein analyses, as well as for cell studies. This confirms the importance of future interdisciplinary collaborations. © 2021 The Author(s). 

  • 3.
    Benselfelt, T.
    et al.
    KTH Royal Institute of Technology, Sweden; Nanyang Technological University, Singapore.
    Kummer, N.
    Empa Swiss Federal Laboratories for Materials Science and Technology, Switzerland; ETH Zürich, Switzerland.
    Nordenström, M.
    KTH Royal Institute of Technology, Sweden.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Nyström, G.
    Empa Swiss Federal Laboratories for Materials Science and Technology, Switzerland; ETH Zürich, Switzerland.
    Wågberg, L.
    KTH Royal Institute of Technology, Sweden.
    The Colloidal Properties of Nanocellulose2023Ingår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 16, nr 8, s. e202201955-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanocelluloses are anisotropic nanoparticles of semicrystalline assemblies of glucan polymers. They have great potential as renewable building blocks in the materials platform of a more sustainable society. As a result, the research on nanocellulose has grown exponentially over the last decades. To fully utilize the properties of nanocelluloses, a fundamental understanding of their colloidal behavior is necessary. As elongated particles with dimensions in a critical nanosize range, their colloidal properties are complex, with several behaviors not covered by classical theories. In this comprehensive Review, we describe the most prominent colloidal behaviors of nanocellulose by combining experimental data and theoretical descriptions. We discuss the preparation and characterization of nanocellulose dispersions, how they form networks at low concentrations, how classical theories cannot describe their behavior, and how they interact with other colloids. We then show examples of how scientists can use this fundamental knowledge to control the assembly of nanocellulose into new materials with exceptional properties. We hope aspiring and established researchers will use this Review as a guide. © 2023 The Authors. 

  • 4.
    Berta, Marco
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Koelewijn, Ingrid
    University of Applied Sciences HAS Den Bosch, Netherlands.
    Johansson, Kalle
    Lyckeby Starch AB, Sweden.
    Stading, Mats
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel. Chalmers University of Technology, Sweden.
    Effect of cellulose-based hydrocolloids and starch chemical modification on the rheology of gluten-free dough2017Ingår i: Annual Transactions of the Nordic Rheology Society, Vol. 25, s. 77-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study was carried out to evaluate the effect of cellulose-based hydrocolloids on the rheology of flour doughs based on corn starch and potato starch. Adding cellulosebased hydrocolloids or a chemically modified waxy starch to this gluten-free dough imparted a shear-thinning behavior similar to that of wheat flour dough.

  • 5.
    Berta, Marco
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Moser, Josefine
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Lopez-Sanchez, Patricia
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Stading, Mats
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel. Chalmers University of Technology, Sweden.
    Modelling the continuous relaxation time spectrum of aqueous xanthan solutions using two commercial softwares2018Ingår i: Annual Transactions of the Nordic Rheology Society, Vol. 26, s. 183-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    ABSTRACT The continuous relaxation time spectrum was modelled from the mechanical spectrum of a xanthan aqueous solution both using the TA Instruments TRIOS® software, and with the rheology software IRIS®1 . Two types of calculation were applied to obtain the relaxation modes since the software bundles used in this study base the calculation upon two different algorithms, named “parsimonious” as it models continuous relaxation spectra using a minimum number of modes to obtain continuous relaxation times2 , and a nonlinear regularization method that provides a larger spectrum with several modes3 . The results were overall comparable but slightly different for long relaxation times.

  • 6.
    Besharat, Zahra
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wakeham, Deborah
    KTH Royal Institute of Technology, Sweden.
    Johnson, C. Magnus
    KTH Royal Institute of Technology, Sweden.
    Luengo, Gustavo S.
    L’Oréal Research and Innovation, France.
    Greaves, Andrew
    L’Oréal Research and Innovation, France.
    Odnevall Wallinder, Inger
    KTH Royal Institute of Technology, Sweden.
    Göthelid, Mats
    KTH Royal Institute of Technology, Sweden.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Mixed monolayers of alkane thiols with polar terminal group on gold: Investigation of structure dependent surface properties2016Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 484, s. 279-290Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Adsorption of thiols with cationic or anionic terminal group on gold has been studied from mixed solutions of 11-Amino-1-undecanethiol (AUT) and 3-Mercaptopropionic acid (MPA) using Quartz Crystal Microbalance with Dissipation (QCM-D), X-ray Photoelectron Spectroscopy (XPS), atomic force microscopy (AFM) and contact angles. The goal is to probe the nature of such layers, and the additivity or otherwise of the pH responsiveness, with a view to evaluate their suitability as smart materials. For each of the two pure (unmixed) cases, ordered molecular monolayers are formed with sulfur binding to gold and the alkane chain pointing out from the surface as expected. Adsorption from the thiol mixtures, however, leads to a more complex behaviour. The surface concentration of thiols from the mixtures, as determined by QCM-D, is considerably lower than for the pure cases and it reaches a minimum at a 3:1 MPA/AUT relative concentration in the solution. The XPS results confirm a reduction in adsorbed amount in mixtures with the lowest overall intensity for the 3:1 ratio. Monolayers formed from mixtures display a wettability which is much lower and less pH sensitive. Collectively these results confirm that for adsorption from mixed systems, the configuration is completely different. Complex formation in the mixed solutions leads to the adsorption of molecules parallel to the surface in an axially in-plane configuration. This parallel layer of thiols is mechanically relatively robust to nano-shaving based on AFM measurements. These results will have a significant impact on the design of biomimetic surface coatings particularly when mixtures of oppositely charged molecules are present on the surface, as is commonly the case in biological, proteinaceous surfaces (e.g. hair and skin).

  • 7.
    Bełdowski, Piotr
    et al.
    Bydgoszcz University of Science & Technology, Poland; KTH Royal Institute of Technology, Sweden.
    Przybyłek, Maciej
    Nicolaus Copernicus University, Poland.
    Raczyński, Przemysław
    University of Silesia, Poland.
    Dedinaite, Andra
    RISE Research Institutes of Sweden. KTH Royal Institute of Technology, Sweden.
    Górny, Krzysztof
    University of Silesia, Poland.
    Wieland, Florian
    Helmholtz-Zentrum Hereon Institute for metallic Biomaterials, Germany.
    Dendzik, Zbigniew
    University of Silesia, Poland.
    Sionkowska, Alina
    Nicolaus Copernicus University, Poland.
    Claesson, Per M
    KTH Royal Institute of Technology, Sweden.
    Albumin–hyaluronan interactions: Influence of ionic composition probed by molecular dynamics2021Ingår i: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 22, nr 22, artikel-id 12360Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The lubrication mechanism in synovial fluid and joints is not yet fully understood. Nevertheless, intermolecular interactions between various neutral and ionic species including large macromolecular systems and simple inorganic ions are the key to understanding the excellent lubrication performance. An important tool for characterizing the intermolecular forces and their structural consequences is molecular dynamics. Albumin is one of the major components in synovial fluid. Its electrostatic properties, including the ability to form molecular complexes, are closely related to pH, solvation, and the presence of ions. In the context of synovial fluid, it is relevant to describe the possible interactions between albumin and hyaluronate, taking into account solution composition effects. In this study, the influence of Na+, Mg2+, and Ca2+ ions on human serum albumin–hyaluronan interactions were examined using molecular dynamics tools. It was established that the presence of divalent cations, and especially Ca2+, contributes mostly to the increase of the affinity between hyaluronan and albumin, which is associated with charge compensation in negatively charged hyaluronan and albumin. Furthermore, the most probable binding sites were structurally and energetically characterized. The indicated moieties exhibit a locally positive charge which enables hyaluronate binding (direct and water mediated). © 2021 by the authors

  • 8.
    Bogdanova, E.
    et al.
    Malmö University, Sweden.
    Lages, S.
    Malmö University, Sweden; Lund University, Sweden.
    Phan-Xuan, T.
    Malmö University, Sweden; Lund University, Sweden: NovoNordiskA/S, Denmark.
    Kamal, M. A.
    Malmö University, Sweden; Lund University, Sweden.
    Terry, A.
    Lund University, Sweden.
    Millqvist-Fureby, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Kocherbitov, V.
    Malmö University, Sweden.
    Lysozyme-Sucrose Interactions in the Solid State: Glass Transition, Denaturation, and the Effect of Residual Water2023Ingår i: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The freeze-drying of proteins, along with excipients, offers a solution for increasing the shelf-life of protein pharmaceuticals. Using differential scanning calorimetry, thermogravimetric analysis, sorption calorimetry, and synchrotron small-angle X-ray scattering (SAXS), we have characterized the properties at low (re)hydration levels of the protein lysozyme, which was freeze-dried together with the excipient sucrose. We observe that the residual moisture content in these samples increases with the addition of lysozyme. This results from an increase in equilibrium water content with lysozyme concentration at constant water activity. Furthermore, we also observed an increase in the glass transition temperature (Tg) of the mixtures with increasing lysozyme concentration. Analysis of the heat capacity step of the mixtures indicates that lysozyme does not participate in the glass transition of the sucrose matrix; as a result, the observed increase in the Tg of the mixtures is the consequence of the confinement of the amorphous sucrose domains in the interstitial space between the lysozyme molecules. Sorption calorimetry experiments demonstrate that the hydration behavior of this formulation is similar to that of the pure amorphous sucrose, while the presence of lysozyme only shifts the sucrose transitions. SAXS analysis of amorphous lysozyme-sucrose mixtures and unfolding of lysozyme in this environment show that prior to unfolding, the size and shape of lysozyme in a solid sucrose matrix are consistent with its native state in an aqueous solution. The results obtained from our study will provide a better understanding of the low hydration behavior of protein-excipient mixtures and support the improved formulation of biologics. © 2023 The Authors. 

  • 9.
    Bogdanova, Ekaterina
    et al.
    Biofilms research center for Biointerfaces, Sweden; Malmö University, Sweden.
    Millqvist-Fureby, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Kocherbitov, Vitaly
    Biofilms research center for Biointerfaces, Sweden; Malmö University, Sweden.
    Hydration enthalpies of amorphous sucrose, trehalose and maltodextrins and their relationship with heat capacities.2021Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 23, nr 26, s. 14433-14448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mechanisms of glass transitions and the behavior of small solute molecules in a glassy matrix are some of the most important topics of modern thermodynamics. Water plays an important role in the physical and chemical stability of lyophilized biologics formulations, in which glassy carbohydrates act as cryoprotectants and stabilizers. In this study, sorption calorimetry was used for simultaneous measurements of water activity and the enthalpy of water sorption by amorphous sucrose, trehalose and maltodextrins. Moreover, the heat capacity of these carbohydrates in mixtures with water was measured by DSC in a broad range of water contents. The hydration enthalpies of glassy sucrose, trehalose and maltodextrins are exothermic, and the enthalpy change of water-induced isothermal glass transitions is higher for small molecules. The partial molar enthalpy of mixing of water in slow experiments is about -18 kJ mol-1, but less exothermic in the case of small molecules at fast hydration scan rates. By measuring the heat capacities of disaccharides and maltodextrins as a function of water content, we separated the contributions of carbohydrates and water to the total heat capacities of the mixtures. The combination of these data allowed testing of thermodynamic models describing the hydration-induced glass transitions. The heat capacity changes calculated by the fitting of the hydration enthalpy data for disaccharides are in good agreement with the heat capacity data obtained by DSC, while for maltodextrins, the effect of sub-Tg transitions should be taken into account. Combining the data obtained by different techniques, we found a distinct difference in the behavior of water in glassy polymers compared to that in glassy disaccharides. By understanding the behavior of water in glassy carbohydrates, these results can be used to improve the design of freeze-dried formulations of proteins and probiotics.

  • 10.
    Bogdanova, Ekaterina
    et al.
    Malmö University, Sweden; Biofilms research center for Biointerfaces, Sweden; NextBioForm Competence Centre, Sweden.
    Millqvist-Fureby, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Kocherbitov, Vitaly
    Malmö University, Sweden; Biofilms research center for Biointerfaces, Sweden; NextBioForm Competence Centre, Sweden.
    Influence of Cooling Rate on Ice Crystallization and Melting in Sucrose-Water System2022Ingår i: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 111, nr 7, s. 2030-2037Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ice crystallization and melting in systems where the equilibrium state is difficult to reach is one of the growing areas in pharmaceutical freeze-drying research. The quality of the final freeze-dried product depends on the parameters of the cooling step, which affect the ice nucleation and growth. In this paper, we present a DSC study of ice crystallization and melting in a sucrose-water system. Using two different types of thermal cycles, we examine the influence of cooling and heating rates on the thermal behavior of sucrose-water solutions with water contents between 50 and 100 wt%. The DSC results show that low cooling rates provide crystallization at higher temperatures and lead to lower amount of non-freezing water. Consequently, the glass transition and ice melting properties observed upon heating depend on the cooling conditions in the preceding step. Based on the experimental results, we investigate the reasons for the existence of the two steps on DSC heating curves in sucrose-water systems: the glass transition step and the onset of ice melting. We show that diffusion of water can be the limiting factor for ice growth and melting in the sucrose-water system when the amorphous phase is in a liquid state. In particular, when the diffusion coefficient drops below 10−14 m2/sec, the ice crystals growth or melting becomes strongly suppressed even above the glass transition temperature. Understanding the diffusion limitations in the sucrose-water system can be used for the optimization of the freeze-drying protocols for proteins and probiotics. © 2022 The Authors

  • 11.
    Boge, Lukas
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. Chalmers University of Technology, Sweden.
    Bysell, Helena
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Ringstad, Lovisa
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Wennman, David
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Process Development, Analys och fastfas.
    Umerska, Anita
    University of Angers, France.
    Cassisa, Viviane
    CHU Angers, France.
    Eriksson, Jonny
    Uppsala University, Sweden.
    Joly-Guillou, Marie-Laure
    CHU Angers, France.
    Edwards, Katarina
    Uppsala University, Sweden.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Lipid-based liquid crystals as carriers for antimicrobial peptides: Phase behavior and antimicrobial effect2016Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, nr 17, s. 4217-4228Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The number of antibiotic-resistant bacteria is increasing worldwide, and the demand for novel antimicrobials is constantly growing. Antimicrobial peptides (AMPs) could be an important part of future treatment strategies of various bacterial infection diseases. However, AMPs have relatively low stability, because of proteolytic and chemical degradation. As a consequence, carrier systems protecting the AMPs are greatly needed, to achieve efficient treatments. In addition, the carrier system also must administrate the peptide in a controlled manner to match the therapeutic dose window. In this work, lyotropic liquid crystalline (LC) structures consisting of cubic glycerol monooleate/water and hexagonal glycerol monooleate/oleic acid/water have been examined as carriers for AMPs. These LC structures have the capability of solubilizing both hydrophilic and hydrophobic substances, as well as being biocompatible and biodegradable. Both bulk gels and discrete dispersed structures (i.e., cubosomes and hexosomes) have been studied. Three AMPs have been investigated with respect to phase stability of the LC structures and antimicrobial effect: AP114, DPK-060, and LL-37. Characterization of the LC structures was performed using small-angle X-ray scattering (SAXS), dynamic light scattering, ζ-potential, and cryogenic transmission electron microscopy (Cryo-TEM) and peptide loading efficacy by ultra performance liquid chromatography. The antimicrobial effect of the LCNPs was investigated in vitro using minimum inhibitory concentration (MIC) and time-kill assay. The most hydrophobic peptide (AP114) was shown to induce an increase in negative curvature of the cubic LC system. The most polar peptide (DPK-060) induced a decrease in negative curvature while LL-37 did not change the LC phase at all. The hexagonal LC phase was not affected by any of the AMPs. Moreover, cubosomes loaded with peptides AP114 and DPK-060 showed preserved antimicrobial activity, whereas particles loaded with peptide LL-37 displayed a loss in its broad-spectrum bactericidal properties. AMP-loaded hexosomes showed a reduction in antimicrobial activity.

  • 12.
    Claesson, Per M
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wojas, Natalia
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Corkery, Robert
    KTH Royal Institute of Technology, Sweden.
    Dedinaite, Andra
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel. KTH Royal Institute of Technology, Sweden.
    Schoelkopf, Joachim
    Omya International AG, Switzerland.
    Tyrode, Eric
    KTH Royal Institute of Technology, Sweden.
    The dynamic nature of natural and fatty acid modified calcite surfaces2023Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Calcium carbonate, particularly in the form of calcite, is an abundant mineral widely used in both human-made products and biological systems. The calcite surface possesses a high surface energy, making it susceptible to the adsorption of organic contaminants. Moreover, the surface is also reactive towards a range of chemicals, including water. Consequently, studying and maintaining a clean and stable calcite surface is only possible under ultrahigh vacuum conditions and for limited amounts of time. When exposed to air or solution, the calcite surface undergoes rapid transformations, demanding a comprehensive understanding of the properties of calcite surfaces in different environments. Similarly, attention must also be directed towards the kinetics of changes, whether induced by fluctuating environments or at constant condition. All these aspects are encompassed in the expression “dynamic nature”, and are of crucial importance in the context of the diverse applications of calcite. In many instances, the calcite surface is modified by adsorption of fatty acids to impart a desired nonpolar character. Although the binding between carboxylic acid groups and calcite surfaces is strong, the fatty acid layer used for surface modification undergoes significant alterations when exposed to water vapour and liquid water droplets. Therefore, it is also crucial to understand the dynamic nature of the adsorbed layer. This review article provides a comprehensive overview of the current understanding of both the dynamics of the calcite surface as well as when modified by fatty acid surface treatments. Calcium carbonate, particularly in the form of calcite and surface modified calcite, is an abundant mineral widely used in both human-made and biological systems.

  • 13.
    Colombo, Stefan
    et al.
    Uppsala University, Sweden.
    Brisander, Magnus
    XSpray Microparticles AB, Sweden.
    Haglöf, Jakob
    Uppsala University, Sweden.
    Sjövall, Peter
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Andersson, Per
    XSpray Microparticles AB, Sweden.
    Østergaard, Jesper
    University of Copenhagen, Denmark.
    Malmsten, Martin
    Uppsala University, Sweden.
    Matrix effects in nilotinib formulations with pH-responsive polymer produced by carbon dioxide-mediated precipitation2015Ingår i: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 494, nr 1, s. 205-217, artikel-id 15114Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Factors determining the pH-controlled dissolution kinetics of nilotinib formulations with the pH-titrable polymer hydroxypropyl methylcellulose phthalate, obtained by carbon dioxide-mediated precipitation, were mechanistically examined in acid and neutral environment. The matrix effect, modulating the drug dissolution, was characterized with a battery of physicochemical methodologies, including ToF-SIMS for surface composition, SAXS/WAXS and modulated DSC for crystallization characterization, and simultaneous UV-imaging and Raman spectroscopy for monitoring the dissolution process in detail. The hybrid particle formulations investigated consisted of amorphous nilotinib embedded in a polymer matrix in single continuous phase, displaying extended retained amorphicity also under wet conditions. It was demonstrated by Raman and FTIR spectroscopy that the efficient drug dispersion and amorphization in the polymer matrix were mediated by hydrogen bonding between the drug and the phthalate groups on the polymer. Simultaneous Raman and UV-imaging studies of the effect of drug load on the swelling and dissolution of the polymer matrix revealed that high nilotinib load prevented matrix swelling on passage from acid to neutral pH, thereby preventing re-precipitation and re-crystallization of incorporated nilotinib. These findings provide a mechanistic foundation of formulation development of nilotinib and other protein kinase inhibitors, which are now witnessing an intense therapeutic and industrial attention due to the difficulty in formulating these compounds so that efficient oral bioavailability is reached.

  • 14.
    Cooper, Peter K.
    et al.
    University of Newcastle, Australia.
    Li, Hua
    University of Newcastle, Australia.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Webber, Grant B.
    University of Newcastle, Australia.
    Atkin, Rob
    University of Newcastle, Australia.
    Tribotronic control of friction in oil-based lubricants with ionic liquid additives2016Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, nr 34, s. 23657-23662Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Atomic force microscopy (AFM) reveals that tribotronic control of friction using an external potential applied to a gold surface is possible for ionic liquid (IL) concentrations as low as 5 mol% in hexadecane. The IL used is trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate, in which both the cation and anion have surfactant-like structures, and is miscible with hexadecane in all proportions. For IL concentrations less than 5 mol% friction does not vary with applied potential, but for 5 mol% and above changing the potential changes the composition of the IL boundary layer from cation-enriched (negative potentials) to anion-enriched (positive potentials). As the lubricities of the cation-rich and anion-rich boundary layers differ, this enables active control of friction in oil-based lubricants.

  • 15.
    Dobryden, Illia
    et al.
    Luleå University of Technology, Sweden.
    Steponavičiu̅tė, Medeina
    Vilnius University, Lithuania.
    Hedman, Daniel
    Luleå University of Technology, Sweden; Institute for Basic Science, South Korea.
    Klimkevičius, Vaidas
    Vilnius University, Lithuania.
    Makuška, Ricardas
    Vilnius University, Lithuania.
    Dėdinaitė, Andra
    RISE Research Institutes of Sweden. KTH Royal Institute of Technology, Sweden.
    Liu, Xioayan
    Shaanxi Normal University, China.
    Corkery, Robert
    KTH Royal Institute of Technology, Sweden.
    Claesson, Per Martin
    KTH Royal Institute of Technology, Sweden.
    Local Wear of Catechol-Containing Diblock Copolymer Layers: Wear Volume, Stick-Slip, and Nanomechanical Changes2021Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 125, nr 38, s. 21277-21292Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polymers containing catechol groups have gained a large interest, as they mimic an essential feature of mussel adhesive proteins that allow strong binding to a large variety of surfaces under water. This feature has made this class of polymers interesting for surface modification purposes, as layer functionalities can be introduced by a simple adsorption process, where the catechol groups should provide a strong anchoring to the surface. In this work, we utilize an AFM-based method to evaluate the wear resistance of such polymer layers in water and compare it with that offered by electrostatically driven adsorption. We pay particular attention to two block copolymer systems where the anchoring group in one case is an uncharged catechol-containing block and in the other case a positively charged and catechol-containing block. The wear resistance is evaluated in terms of wear volume, and here, we compare with data for similar copolymers with statistical distribution of the catechol groups. Monitoring of nanomechanical properties provides an alternative way of illustrating the effect of wear, and we use modeling to show that the stiffness, as probed by an AFM tip, of the soft layer residing on a hard substrate increases as the thickness of the layer decreases. The stick-slip characteristics are also evaluated. © 2021 The Authors. 

  • 16.
    Dudek, M.
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Ruwoldt, Jost
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. NTNU Norwegian University of Science and Technology, Norway.
    Øye, G.
    NTNU Norwegian University of Science and Technology, Norway.
    Characterization and assessment of wax and wax inhibitors systems in microfluidic oil-in-water coalescence experiments2022Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 636, artikel-id 128186Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During produced water treatment, one of the key underlying phenomena affecting separation performance is coalescence between oil droplets. These processes can be affected by several factors, including chemical composition of fluids, process conditions, droplet characteristics, but also presence of different production chemicals. In this paper, we study the effect of wax and wax inhibitors on the stability of oil droplets in brine with a microfluidic coalescence method. Three wax inhibitors with known chemistries were added to crude oil and solutions of macrocrystalline wax in dodecane. All the systems were characterized with regards to their physicochemical, rheological and interfacial properties, while the microfluidic coalescence measurements were performed below and above the wax appearance temperature. In most cases, higher concentration of the inhibitors lowered the coalescence frequency between the droplets, however the presence of wax often reduced the stabilizing effect of the additives. The most stable emulsions, often by 1–2 orders of magnitude, were obtained for the polycarboxylate wax inhibitor with the lowest molecular weight and exhibiting highest interfacial activity. Styrene block copolymer was also found to prevent coalescence, most likely by changing the mechanical properties of the interface, however this was strongly affected by the concentration of wax in the solution. Higher temperature mostly affected the inhibitor-paraffin or inhibitor-solvent interactions, which resulted in increase or reduction of emulsion stability, depending on the inhibitor. Crude oil systems, more stable than model solutions to begin with, were found to be only slightly affected by the presence of additives. This was mostly attributed to the abundance presence of crude oil indigenous surface-active components. Still, in all cases when an additive was present, the stability of droplets increased. Overall, this study underlines the importance of non-separation related production chemicals within the wider frame of separation processes in upstream petroleum processing. © 2021 The Author(s)

  • 17.
    Eneborg, Alexander
    RISE - Research Institutes of Sweden, Biovetenskap och material, Yta, process och formulering. KTH Royal Institute of Technology, Sweden.
    Improvement and Characterization of Aqueous Graphene Dispersions2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Grafen har många otroliga egenskaper som gör det till en bra kandidat för ny teknologi. I dagsläget är det fortfarande dyrt och komplicerat att producera stora ark med grafen, men det finns många applikationer där det inte är nödvändigt och mindre grafenflagor istället kan användas. Ett användbart sätt att hanteradessa grafenflagor är i en dispersion, speciellt en vattenbaserad dispersion har många fördelar. En sådan stabil dispersion av funktionaliserade grafenflagor har producerats, förbättrats och karaktäriserats idetta projekt. Ett vattenbaserat system utvecklat i två tidigare M.Sc. projekt, där det ena bestämde ett bra kommersiellt grafenpulver och det andra en bra stabilisator, användes som en startpunkt med huvudsyftet att öka andelen grafen från pulvret som dispergeras. Den metod som används för att producera dessa dispersioner kan beskrivas som sonikering av grafenpulver i en lösning av vatten och stabilisator följt av centrifugering för att avlägsna icke-dispergerade grafenflagor. Experiment utfördes för att utvärdera möjligheten att dispergera dem tidigare icke-dispergerade grafenflagorna, kombinera stabilisatorn med flera tensider, optimera centrifugeringshastighet och tid, raffinera sonikeringsprocessen med förlängd exponeringstid och kylning, smalna av stabilisatorns storleksfördelning med ultrafiltrering och avlägsnande av överflödig icke-bunden stabilisator genom ultrafiltrering. Prover karekteriserades med UV-vis, SEM, TGA, Elektroforetisk ljusspridning, och Laserdiffraktionsspektroskopi. Det uptäcktes att inlösningsgraden av grafen var starkt beroende av sonikeringstid och centrifugeringsparametrar. Ökningen i grafenkoncentration från sonikeringstid visade att majoriteten,om inte alla, av de tidigare icke-inlösta grafenflagorna kunde dispergeras. I en industriell miljö så kunde alla icke-inlösta grafenflagor helt enkelt tillsättas i nästa omgång av processen. Att minska centrifugeringshastigeten och tiden ökade grafen koncentrationen till mer än det dubbla jämfört med de tidigare använda parametrarna, och den ökningen kommer helt från större grafenflagor. Således har dettidigare problemet med låg inlösningsgrad visats bero på för lite sonikering och för mycketcentrifugering. Partikelstorleksanalysen visade en liten minskning av flakstorleken vid längre sonikeringstider, dock visade SEM analysen av dem proverna att alla bildade jämna filmer utan synbara skillnader mellan proverna. Reningsprocessen via ultrafiltrering utfördes på uppskalade prover till tre olika nivåer, 0 %, 50 % och 95 %, för totalt tre 100 ml dispersioner. Alla dessa tre dispersioner visade sig vara högst stabila, utan minskning i grafen koncentration under 5 veckor och en zeta potential under-50 mV. TGA resultaten förstärkte UV-vis resultaten och visade att reningsprocessen fungerade som den skulle.

  • 18.
    Eriksson, Mimmi
    et al.
    RISE Research Institutes of Sweden. KTH Royal Institute of Technology, Sweden.
    Claesson, Per M
    KTH Royal Institute of Technology, Sweden.
    Järn, Mikael
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Wallqvist, Viveca
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Tuominen, Mikko
    RISE Research Institutes of Sweden.
    Kappl, Michael
    Max Planck Institute, Germany.
    Teisala, Hannu
    Max Planck Institute, Germany.
    Vollmer, Doris
    Max Planck Institute, Germany.
    Schoelkopf, Joachim
    Omya International AG, Switzerland.
    Gane, Patrick
    Aalto University, Finland; University of Belgrade, Serbia.
    Mäkelä, Jyrki
    Tampere University, Finland.
    Swerin, Agne
    KTH Royal Institute of Technology, Sweden; Karlstad University, Sweden.
    Effects of liquid surface tension on gas capillaries and capillary forces at superamphiphobic surfaces2023Ingår i: Scientific Reports, E-ISSN 2045-2322, Vol. 13, nr 1, artikel-id 6794Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The formation of a bridging gas capillary between superhydrophobic surfaces in water gives rise to strongly attractive interactions ranging up to several micrometers on separation. However, most liquids used in materials research are oil-based or contain surfactants. Superamphiphobic surfaces repel both water and low-surface-tension liquids. To control the interactions between a superamphiphobic surface and a particle, it needs to be resolved whether and how gas capillaries form in non-polar and low-surface-tension liquids. Such insight will aid advanced functional materials development. Here, we combine laser scanning confocal imaging and colloidal probe atomic force microscopy to elucidate the interaction between a superamphiphobic surface and a hydrophobic microparticle in three liquids with different surface tensions: water (73 mN m−1), ethylene glycol (48 mN m−1) and hexadecane (27 mN m−1). We show that bridging gas capillaries are formed in all three liquids. Force-distance curves between the superamphiphobic surface and the particle reveal strong attractive interactions, where the range and magnitude decrease with liquid surface tension. Comparison of free energy calculations based on the capillary menisci shapes and the force measurements suggest that under our dynamic measurements the gas pressure in the capillary is slightly below ambient. © 2023, The Author(s).

  • 19.
    Ernstsson, Marie
    et al.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Dedinaite, Andra
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel. KTH Royal Institute of Technology, Sweden.
    Rojas, Orlando J
    University of British Columbia, Canada.
    Claesson, Per M
    KTH Royal Institute of Technology, Sweden.
    Two different approaches to XPS quantitative analysis of polyelectrolyte adsorption layers2023Ingår i: Surface and Interface Analysis, ISSN 0142-2421, E-ISSN 1096-9918, Vol. 55, nr 1, s. 26-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    X-ray photoelectron spectroscopy (XPS) was employed to quantify adsorption of polyelectrolytes from aqueous solutions of low ionic strength onto mica, glass, and silica. Silica surfaces were conditioned in base or in acid media as last pre-treatment step (silica-base last or silica-acid last, respectively). Consistency in the determined adsorbed amount, Γ, was obtained independent of the choice of XPS mode and with the two quantification approaches used in the data evaluation. Under the same adsorption conditions, the adsorbed amount, Γ, varied as Γmica &gt; Γsilica-base last ≈ Γglass &gt; Γsilica-acid last. In addition, the adsorbed amount increased with decreasing polyelectrolyte charge density (100% to 1% of segments being charged) for all substrates. Large adsorbed amount was measured for low-charge density polyelectrolytes, but the number of charged segments per square nanometer was low due to steric repulsion between polyelectrolyte chains that limited the adsorption. The adsorbed amount of highly charged polyelectrolytes was controlled by electrostatic interactions and thus limited to that needed to neutralize the substrate surface charge density. For silica, the adsorbed amount depended on the cleaning method, suggesting that this process influenced surface concentration and fraction of different silanol groups. Our results demonstrate that for silica, a higher density and/or more acidic silanol groups are formed using base, rather than acid, treatment in the last step. © 2022 The Authors.

  • 20.
    Falk, Julia
    RISE - Research Institutes of Sweden, Biovetenskap och material, Yta, process och formulering. Uppsala University, Sweden.
    Freeze-drying of protein pharmaceutical in vials with different character2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Freeze-drying of protein pharmaceuticals is a procedure frequently used to obtain stability of the active pharmaceutical ingredientduring distribution and storage. It can be performed in pre-filled syringes, with a lubricous coating of silicone on the inside, to enable the piston moving. The coating changes the environment potentially affecting the features of the freeze-dried cake since the wetting behavior and adhesion to the inner wall is affected.This project aimed to investigate the effect of the siliconization of the cakes. Three different formulations were freeze-dried in nonsiliconized (NS) and siliconized vials using different siliconization protocols. Analysis was done using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA),scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and an embedding method, intended to give information about the cake’s shrinkage, cracking and pore-structure. The water content in the bottom of the cakes was consistently higher than in the top, a difference decreasing over time. Increased surface hydrophobicity lead to increased shrinkage of the cake’s volume and a decrease in fogging. The bottom of the protein cake in the vial siliconized with a commercial silicone emulsion consisted of pores with regularly equal pore size and thick pore walls, a structure not seen in any other cake. All cakes in the silicone emulsion siliconized vials had lower water content than the cakes in the vials using the other siliconization method. The XPS-analysis showed that the cakes in the emulsion siliconized vials contained silicon, indicating an excess of silicone when siliconizing and/or an unstable coating.

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  • 21.
    Gericke, Sabrina
    et al.
    Lund University, Sweden.
    Rissler, Jenny
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. Lund University, Sweden.
    Bermeo, Marie
    Lund University, Sweden.
    Wallander, Harald
    Malmö University, Sweden.
    Karlsson, Hanna
    Lund University, Sweden.
    Kollberg, Linnea
    Lund University, Sweden.
    Scardamaglia, Mattia
    Lund University, Sweden.
    Temperton, Robert
    Lund University, Sweden.
    Zhu, Suyun
    Lund University, Sweden.
    Sigfridsson Clauss, Kajsa
    Lund University, Sweden.
    Hulteberg, Christian
    Lund University, Sweden.
    Shavorskiy, Andrey
    Lund University, Sweden.
    Merte, L. R
    Malmö University, Sweden.
    Messing, Marie Elise
    Lund University, Sweden.
    Zetterberg, Johan
    Lund University, Sweden.
    Blomberg, Sara
    Lund University, Sweden.
    In Situ H2 Reduction of Al2O3-Supported Ni- and Mo-Based Catalysts2022Ingår i: Catalysts, E-ISSN 2073-4344, Vol. 12, nr 7, artikel-id 755Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nickel (Ni)-promoted Molybdenum (Mo)-based catalysts are used for hydrotreatment processes in the chemical industry where the catalysts are exposed to high-pressure H2 at elevated temperature. In this environment, the catalyst transforms into the active phase, which involves the reduction of the oxide. Here, we report on the first in situ study on the reduction of alumina supported Ni- and Mo-based catalysts in 1 mbar H2 using ambient-pressure X-ray photoelectron spectroscopy (APXPS). The study confirms that mixing Ni and Mo lowers the reduction temperature of both Ni- and Mo-oxide as compared to the monometallic catalysts and shows that the MoO3 reduction starts at a lower temperature than the reduction of NiO in NiMo/Al2O3 catalysts. Additionally, the reduction of Ni and Mo foil was directly compared to the reduction of the Al2O3-supported catalysts and it was observed that the reduction of the supported catalysts is more gradual than the reduction of the foils, indicating a strong interaction between the Ni/Mo and the alumina support. © 2022 by the authors.

  • 22.
    Gårdebjer, Sofie
    et al.
    Chalmers University of Technology, Sweden.
    Andersson, M.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Engström, J.
    AkzoNobel, Sweden.
    Restorp, P.
    AkzoNobel, Sweden.
    Persson, Michael
    Chalmers University of Technology, Sweden; AkzoNobel, Sweden.
    Larsson, Anette
    Chalmers University of Technology, Sweden.
    Using Hansen solubility parameters to predict the dispersion of nano-particles in polymeric films2016Ingår i: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 7, nr 9, s. 1756-1764Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We suggest a rough and straightforward method to predict the dispersibility of modified cellulose nanocrystals (CNC) in nanocomposites using Hansen solubility parameters (HSP). The surface of CNC was modified using a novel approach where Y-shaped substituents with two different carbon chain lengths were attached to the surface. Approximate HSP values were calculated for the modified CNC, and dispersions of unmodified and modified CNC in solvents with varying HSPs were studied. The best dispersibility was observed in dichloromethane, when the CNC surface was modified with longer carbon chains. Dichloromethane has HSP similar to low-density polyethylene (LDPE). Nanocomposites with both unmodified and modified CNC were produced. The materials with modified CNC showed increased adhesion between the filler and the matrix, followed by a decreased water permeability compared to unmodified CNC, suggesting a better dispersibility of modified CNC in LDPE and confirming the usefulness of this approach.

  • 23.
    Hammond, Oliver
    et al.
    Stockholm University, Sweden; Aarhus University, Denmark.
    Bousrez, Guillaume
    Stockholm University, Sweden; Aarhus University, Denmark.
    Mehler, Filip
    KTH Royal Institute of Technology, Sweden.
    Li, Sichao
    KTH Royal Institute of Technology, Sweden.
    Shimpi, Manishkumar
    Stockholm University, Sweden; Luleå University of Technology, Sweden.
    Doutch, James
    Rutherford Appleton Laboratory, UK.
    Cavalcanti, Leide
    Rutherford Appleton Laboratory, UK.
    Glavatskih, Sergei
    KTH Royal Institute of Technology, Sweden; University of New South Wales, Australia; Ghent University, Belgium.
    Antzutkin, Oleg
    Luleå University of Technology, Sweden.
    Rutland, Mark W.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. KTH Royal Institute of Technology, Sweden; University of New South Wales, Australia; École Centrale de Lyon, France.
    Mudring, A. -V
    Stockholm University, Sweden; Aarhus University, Denmark.
    Molecular Architecture Effects on Bulk Nanostructure in Bis(Orthoborate) Ionic Liquids2023Ingår i: Small, ISSN 1613-6810, E-ISSN 1613-6829Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of 19 ionic liquids (ILs) based on phosphonium and imidazolium cations of varying alkyl-chain lengths with the orthoborate anions bis(oxalato)borate [BOB]−, bis(mandelato)borate, [BMB]− and bis(salicylato)borate, [BScB]−, are synthesized and studied using small-angle neutron scattering (SANS). All measured systems display nanostructuring, with 1-methyl-3-n-alkyl imidazolium-orthoborates forming clearly bicontinuous L3 spongelike phases when the alkyl chains are longer than C6 (hexyl). L3 phases are fitted using the Teubner and Strey model, and diffusely-nanostructured systems are primarily fitted using the Ornstein-Zernicke correlation length model. Strongly-nanostructured systems have a strong dependence on the cation, with molecular architecture variation explored to determine the driving forces for self-assembly. The ability to form well-defined complex phases is effectively extinguished in several ways: methylation of the most acidic imidazolium ring proton, replacing the imidazolium 3-methyl group with a longer hydrocarbon chain, substitution of [BOB]− by [BMB]−, or exchanging the imidazolium for phosphonium systems, irrespective of phosphonium architecture. The results suggest there is only a small window of opportunity, in terms of molecular amphiphilicity and cation:anion volume matching, for the formation of stable extensive bicontinuous domains in pure bulk orthoborate-based ILs. Particularly important for self-assembly processes appear to be the ability to form H-bonding networks, which offer additional versatility in imidazolium systems. © 2023 The Authors.

  • 24.
    Hedberg, Yolanda S.
    et al.
    KTH Royal Institute of Technology, Sweden; Karolinska Institute, Sweden.
    Pettersson, Maria
    Uppsala University, Sweden.
    Pradhan, Sulena
    KTH Royal Institute of Technology, Sweden.
    Odnevall Wallinder, Inger
    KTH Royal Institute of Technology, Sweden.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Persson, Cecilia
    Uppsala University, Sweden.
    Can Cobalt(II) and Chromium(III) ions released from joint prostheses influence the friction coefficient?2015Ingår i: ACS Biomaterial Science and Engineering, E-ISSN 2373-9878, Vol. 1, nr 8, s. 617-620Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cobalt chromium molybdenum alloys (CoCrMo) are commonly used as articulating components in joint prostheses. In this tribocorrosive environment, wear debris and metal ionic species are released and interact with proteins, possibly resulting in protein aggregation. This study aimed to investigate whether this could have an effect on the friction coefficient in a typical material couple, namely CoCrMo-on-polyethylene. It was confirmed that both Co(II) and Cr(III) ions, and their combination, at concentrations relevant for the metal release situation, resulted in protein aggregation and its concomitant precipitation, which increased the friction coefficient. Future studies should identify the clinical importance of these findings.

  • 25.
    Hedlund, Jonas
    et al.
    Luleå University of Technology, Sweden.
    Zhou, Ming
    Luleå University of Technology, Sweden.
    Faisal, Abrar
    Luleå University of Technology, Sweden.
    Öhrman, Olov
    RISE Research Institutes of Sweden, Samhällsbyggnad, Energi och resurser. Luleå University of Technology, Sweden.
    Finelli, Valeria
    Università di Torino, Italy.
    Signorile, Matteo
    Università di Torino, Italy.
    Crocellà, Valentina
    Università di Torino, Italy.
    Grahn, Mattias
    Luleå University of Technology, Sweden.
    Controlling diffusion resistance, selectivity and deactivation of ZSM-5 catalysts by crystal thickness and defects2022Ingår i: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 410, s. 320-332Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A systematic investigation of two sets of defect free and defective ZSM-5 crystals with controlled thickness (T) between 30 and 400 nm and of their performances in methanol conversion was reported for the first time in the present work. The defect free ZSM-5 crystals with a thickness of 35 nm are by far the smallest ever reported and displayed superior activity, stability and selectivity to slower diffusing compounds, which resulted in high yield of e.g. gasoline and the 1,2,4-trimethylbenzene isomer with high octane number, as compared to the other studied catalysts. Almost only products forming in the zeolite pores were detected and consequently, the external surface must be nearly inactive. Strong correlations between T and deactivation rate were observed. Thick crystals deactivated much faster than thin crystals, probably due to formation of carbon species in the zeolite pores, which results in pronounced percolation effects and faster deactivation of the former. At comparable thickness, crystals with defects deactivated much faster than defect free crystals, due to formation of additional small molecular coke species in the former. Strong correlations between T and selectivity were also observed and assigned to control of diffusion resistance by crystal thickness. © 2022 The Authors

  • 26.
    Hellsing, Maja
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Yta, process och formulering.
    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 interface2019Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, nr 1, s. 222-228Artikel i tidskrift (Refereegranskat)
    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.

  • 27.
    Heydari, Golrokh
    et al.
    KTH Royal Institute of Technology, Sweden.
    Sedighi Moghaddam, Maziar
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. KTH Royal Institute of Technology, Sweden.
    Tuominen, Mikko
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Fielden, Matthew
    KTH Royal Institute of Technology, Sweden.
    Haapanen, Janne
    TUT Tampere University of Technology, Finland.
    Mäkelä, Jyrki M.
    TUT Tampere University of Technology, Finland.
    Claesson, Per M.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. KTH Royal Institute of Technology, Sweden.
    Wetting hysteresis induced by temperature changes: Supercooled water on hydrophobic surfaces2016Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 468, s. 21-33Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The state and stability of supercooled water on (super)hydrophobic surfaces is crucial for low temperature applications and it will affect anti-icing and de-icing properties. Surface characteristics such as topography and chemistry are expected to affect wetting hysteresis during temperature cycling experiments, and also the freezing delay of supercooled water. We utilized stochastically rough wood surfaces that were further modified to render them hydrophobic or superhydrophobic. Liquid flame spraying (LFS) was utilized to create a multi-scale roughness by depositing titanium dioxide nanoparticles. The coating was subsequently made non-polar by applying a thin plasma polymer layer. As flat reference samples modified silica surfaces with similar chemistries were utilized. With these substrates we test the hypothesis that superhydrophobic surfaces also should retard ice formation. Wetting hysteresis was evaluated using contact angle measurements during a freeze-thaw cycle from room temperature to freezing occurrence at -7 °C, and then back to room temperature. Further, the delay in freezing of supercooled water droplets was studied at temperatures of -4 °C and -7 °C. The hysteresis in contact angle observed during a cooling-heating cycle is found to be small on flat hydrophobic surfaces. However, significant changes in contact angles during a cooling-heating cycle are observed on the rough surfaces, with a higher contact angle observed on cooling compared to during the subsequent heating. Condensation and subsequent frost formation at sub-zero temperatures induce the hysteresis. The freezing delay data show that the flat surface is more efficient in enhancing the freezing delay than the rougher surfaces, which can be rationalized considering heterogeneous nucleation theory. Thus, our data suggests that molecular flat surfaces, rather than rough superhydrophobic surfaces, are beneficial for retarding ice formation under conditions that allow condensation and frost formation to occur.

  • 28.
    Heydari, Golrokh
    et al.
    KTH Royal Institute of Technology, Sweden.
    Tyrode, Erik
    KTH Royal Institute of Technology, Sweden.
    Visnevskij, Ceslav
    Vilnius University, Lithuania.
    Makuska, Ricardas
    Vilnius University, Lithuania.
    Claesson, Per M.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. KTH Royal Institute of Technology, Sweden.
    Temperature-dependent deicing properties of electrostatically anchored branched brush layers of poly(ethylene oxide)2016Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, nr 17, s. 4194-4202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The hydration water of hydrophilic polymers freezes at subzero temperatures. The adsorption of such polymers will result in a hydrophilic surface layer that strongly binds water. Provided this interfacial hydration water remains liquidlike at subzero temperatures, its presence could possibly reduce ice adhesion, in particular, if the liquidlike layer is thicker than or comparable to the surface roughness. To explore this idea, a diblock copolymer, having one branched bottle-brush block of poly(ethylene oxide) and one linear cationic block, was electrostatically anchored on flat silica surfaces. The shear ice adhesion strength on such polymer-coated surfaces was investigated down to -25 °C using a homebuilt device. In addition, the temperature dependence of the ice adhesion on surfaces coated with only the cationic block, only the branched bottle-brush block, and with linear poly(ethylene oxide) was investigated. Significant ice adhesion reduction, in particular, at temperatures above -15 °C, was observed on silica surfaces coated with the electrostatically anchored diblock copolymer. Differential scanning calorimetry measurements on bulk polymer solutions demonstrate different thermal transitions of water interacting with branched and linear poly(ethylene oxide) (with hydration water melting points of about -18 and -10 °C, respectively). This difference is consistent with the low shear ice adhesion strength measured on surfaces carrying branched bottle-brush structured poly(ethylene oxide) at -10 °C, whereas no significant adhesion reduction was obtained with linear poly(ethylene oxide) at this temperature. We propose a lubrication effect of the hydration water bound to the branched bottle-brush structured poly(ethylene oxide), which, in the bulk, does not freeze until -18 °C.

  • 29.
    Hjalmarsson, Nicklas
    et al.
    KTH Royal Institute of Technology, Sweden.
    Atkin, Rob
    University of Newcastle, Australia.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Effect of Lithium ions on rheology and interfacial forces in Ethylammonium Nitrate and Ethanolammonium Nitrate2016Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, nr 47, s. 26960-26967Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of added Li+ to two ionic liquids (ILs), ethylammonium nitrate (EAN) and ethanolammonium nitrate (EtAN), has been investigated using rheology and colloidal probe atomic force microscopy (AFM). Rheology data revealed a complex viscosity dependence that can be ascribed to the different bulk nanostructures. AFM force curves revealed steps for the neat ILs, analogous to those in previous studies. The addition of Li+ broadened the steps, which is likely an effect of ion clusters formed. Friction measurements corroborate this data and also showed that the structure of EtAN is much more prone to change as Li+ is added. These results demonstrate the complex behavior of ILs on interfaces and the effect of perturbing such interactions. (Graph Presented).

  • 30.
    Hjalmarsson, Nicklas
    et al.
    KTH The Royal Institute of Technology, Sweden.
    Atkin, Rob
    University of Newcastle, Australia.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Is the boundary layer of an ionic liquid equally lubricating at higher temperature?2016Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, nr 13, s. 9232-9239Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Atomic force microscopy has been used to study the effect of temperature on normal forces and friction for the room temperature ionic liquid (IL) ethylammonium nitrate (EAN), confined between mica and a silica colloid probe at 25 °C, 50 °C, and 80 °C. Force curves revealed a strong fluid dynamic influence at room temperature, which was greatly reduced at elevated temperatures due to the reduced liquid viscosity. A fluid dynamic analysis reveals that bulk viscosity is manifested at large separation but that EAN displays a nonzero slip, indicating a region of different viscosity near the surface. At high temperatures, the reduction in fluid dynamic force reveals step-like force curves, similar to those found at room temperature using much lower scan rates. The ionic liquid boundary layer remains adsorbed to the solid surface even at high temperature, which provides a mechanism for lubrication when fluid dynamic lubrication is strongly reduced. The friction data reveals a decrease in absolute friction force with increasing temperature, which is associated with increased thermal motion and reduced viscosity of the near surface layers but, consistent with the normal force data, boundary layer lubrication was unaffected. The implications for ILs as lubricants are discussed in terms of the behaviour of this well characterised system.

  • 31.
    Hjalmarsson, Nicklas
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wallinder, Daniel
    Attana AB, Sweden.
    Glavatskih, Sergei
    KTH Royal Institute of Technology, Sweden; Ghent University, Belgium.
    Atkin, Rob
    University of Newcastle, Australia.
    Aastrup, Teodor
    Attana AB, Sweden.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Weighing the surface charge of an ionic liquid2015Ingår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 7, nr 38, s. 16039-16045Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electrochemical quartz crystal microbalance has been used to measure changes in the composition of the capacitive electrical double layer for 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)-trifluorophosphate, an ionic liquid, in contact with a gold electrode surface as a function of potential. The mass difference between the cation and anion means that the technique can effectively "weigh" the surface charge accurately with high temporal resolution. This reveals quantitatively how changing the potential alters the ratio of cations and anions associated with the electrode surface, and thus the charge per unit area, as well as the kinetics associated with these interfacial processes. The measurements reveal that it is diffusion of co-ions into the interfacial region rather than expulsion of counterions that controls the relaxation. The measured potential dependent double layer capacitance experimentally validates recent theoretical predictions for counterion overscreening (low potentials) and crowding (high potentials) at electrode surfaces. This new capacity to quantitatively measure ion composition is critical for ionic liquid applications ranging from batteries, capacitors and electrodeposition through to boundary layer structure in tribology, and more broadly provides new insight into interfacial processes in concentrated electrolyte solutions.

  • 32.
    Huang, Li
    et al.
    University of Modena and Reggio Emilia, Italy.
    Himawan, Erico
    InoCure sro, Czech Republic.
    Belhadj, Soumaya
    University of Tuebingen, Germany.
    Perez, Oswaldo
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Paquet Durand, François
    University of Tuebingen, Germany.
    Schipper, Nicolaas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Buzgo, Matej
    InoCure sro, Czech Republic.
    Simaite, Aiva
    InoCure sro, Czech Republic.
    Marigo, Valeria
    University of Modena and Reggio Emilia, Italy; Center for Neuroscience and Neurotechnology, Italy.
    Efficient Delivery of Hydrophilic Small Molecules to Retinal Cell Lines Using Gel Core-Containing Solid Lipid Nanoparticles2022Ingår i: Pharmaceutics, ISSN 1999-4923, E-ISSN 1999-4923, Vol. 14, nr 1, s. 74-74Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, we developed a novel solid lipid nanoparticle (SLN) formulation for drug delivery of small hydrophilic cargos to the retina. The new formulation, based on a gel core and composite shell, allowed up to two-fold increase in the encapsulation efficiency. The type of hydrophobic polyester used in the composite shell mixture affected the particle surface charge, colloidal stability, and cell internalization profile. We validated SLNs as a drug delivery system by performing the encapsulation of a hydrophilic neuroprotective cyclic guanosine monophosphate analog, previously demonstrated to hold retinoprotective properties, and the best formulation resulted in particles with a size of ±250 nm, anionic charge > −20 mV, and an encapsulation efficiency of ±60%, criteria that are suitable for retinal delivery. In vitro studies using the ARPE-19 and 661W retinal cell lines revealed the relatively low toxicity of SLNs, even when a high particle concentration was used. More importantly, SLN could be taken up by the cells and the release of the hydrophilic cargo in the cytoplasm was visually demonstrated. These findings suggest that the newly developed SLN with a gel core and composite polymer/lipid shell holds all the characteristics suitable for the drug delivery of small hydrophilic active molecules into retinal cells.

  • 33.
    Karlsson, Stefan
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Effects on indentation mechanical properties by chemically strengthening of TiO2 and Al2O3 doped soda lime silicate glasses2022Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Soda lime silicate is an important industrial glass type, it is used in, e.g., windows, containers, household glasses, displays, cover glasses and in automotive glazing. The importance of soda lime silicate glass originates from the forming ability that enables low-cost manufacturing but also relatively high hardness, good chemical durability, and the essential transparency in the visible range. However, soda lime silicate glass suffers from brittleness and has a relatively low resistance towards surface defects. Therefore, is the practical strength of commercially available glass in the soda lime silicate glass family limited. The mechanical properties of glass is of great importance in various applications. Chemical strengthening (CS) of glass has become a successful process that today is used in many applications. It makes glass stronger by exchanging larger ions from a molten salt bath with smaller ions from the glass and thereby inducing compressive stresses in the surface. However, soda lime silicate glass is typically not well-suited for this process and therefore has the effect of dopants on surface mechanical properties as result of CS been studied. Hardness, reduced elastic modulus and crack resistance were studied. The CS was performed in a molten KNO3 salt bath at 450 °C. The results will be discussed in relation to the compositional and structural changes.

  • 34.
    Krona, Annika
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Klose, Felix
    Chalmers University of Technology, Sweden.
    Gold, Julie
    Chalmers University of Technology, Sweden.
    Kadar, Roland
    Chalmers University of Technology, Sweden.
    Stading, Mats
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel. Chalmers University of Technology, Sweden.
    Developing cultured meat scaffolds of extruded vegetable-based proteins2017Ingår i: Annual Transactions of the Nordic Rheology Society, Vol. 25, s. 311-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Muscle cells from animals can becultivated in cell culture medium, but to beused as a meat food product, they need asolid matrix to grow on that can alsocontribute to the texture. In this project wehave created promising fibrous growthsubstrates from extruded plant basedproteins that the cells are able to attach toand grow on. Cultured meat is still far froma commercial product, but may, in the longrun, give even tastier, healthier and moreenvironmentally friendly meat products.

  • 35.
    Kronberg, Bengt
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    The hydrophobic effect2016Ingår i: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 22, s. 14-22Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Abstract This review is a brief discussion on the development of the understanding of hydrophobicity, or the hydrophobic effect. The hydrophobic effect is primarily discussed in terms of partitioning of hydrocarbons between a hydrophobic environment and water as well as solubility of hydrocarbons in water. Micellization of surfactants is only briefly reviewed. It is emphasized that (i) the cause of the hydrophobic effect, e.g. the low solubility of a hydrocarbon in water, is to be found in the high internal energy of water resulting in a high energy to create a cavity in order to accommodate the hydrophobe, (ii) the “structuring” of water molecules around a hydrophobic compound increases the solubility of the hydrophobe. The “structuring” of water molecules around hydrophobic compounds is discussed in terms of recent spectroscopic findings. It is also emphasized that (iii) the lowering of entropy due to a structuring process must be accompanied by an enthalpy that is of the same order of magnitude as the TΔS for the process. Hence, there is an entropy–enthalpy compensation leading to a low free energy change for the structuring process. The assumption of a rapid decay of the entropy with temperature provides an explanation of the enthalpy–entropy compensation so often found in aqueous systems. It is also emphasized (iv) that the free energy obtained from partitioning, or solubility limits, needs to be corrected for molecular size differences between the solute and the solvent. The Flory–Huggins expression is a good first approximation for obtaining this correction. If the effect of different molecular sizes is not corrected for, this leads to erroneous conclusions regarding the thermodynamics of the hydrophobic effect. Finally, (v) micellization and adsorption of surfactants, as well as protein unfolding, are briefly discussed in terms of the hydrophobic effect.

  • 36.
    Larsson, Per Tomas
    et al.
    RISE Research Institutes of Sweden. KTH Royal Institute of Technology, Sweden.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Roth, Stephan
    KTH Royal Institute of Technology, Sweden; DESY, Germany.
    Söderberg, Daniel
    KTH Royal Institute of Technology, Sweden.
    Interpreting SAXS data recorded on cellulose rich pulps2022Ingår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 29, nr 1, s. 117-131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A simulation method was developed for modelling SAXS data recorded on cellulose rich pulps. The modelling method is independent of the establishment of separate form factors and structure factors and was used to model SAXS data recorded on dense samples. An advantage of the modelling method is that it made it possible to connect experimental SAXS data to apparent average sizes of particles and cavities at different sample solid contents. Experimental SAXS data could be modelled as a superposition of a limited number of simulated intensity components and gave results in qualitative agreement with CP/MAS 13C-NMR data recorded on the same samples. For the water swollen samples, results obtained by the SAXS modelling method and results obtained from CP/MAS 13C-NMR measurements, agreed on the ranking of particle sizes in the different samples. The SAXS modelling method is dependent on simulations of autocorrelation functions and the time needed for simulations could be reduced by rescaling of simulated correlation functions due to their independence of the choice of step size in real space. In this way an autocorrelation function simulated for a specific sample could be used to generate SAXS intensity profiles corresponding to all length scales for that sample and used for efficient modelling of the experimental data recorded on that sample. Graphical abstract: [Figure not available: see fulltext.] © 2021, The Author(s).

  • 37.
    Larsson, Per Tomas
    et al.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. KTH Royal Institute of Technology, Sweden.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Roth, Stephan
    DESY, Germany.
    Söderberg, Daniel
    KTH Royal Institute of Technology, Sweden.
    Interpreting SAXS data recorded on cellulose rich pulps2022Ingår i: Cellulose, E-ISSN 1572-882X, Vol. 29, s. 117-131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose rich and cellulose enriched pulps are com. important and scientifically interesting materials with a complex hierarchical fiber wall nanostructure which change with moisture sorption and swelling in water. The fiber wall building blocks and cavities are in size ranges addressable by small angle x-ray scattering (SAXS) but due to large variability in sizes and shapes, extracting quant. data about the fiber wall nanostructure from SAXS data can be challenging. For this purpose, a simulation method was developed for modeling SAXS data recorded on cellulose rich pulps. The modeling method is independent of the establishments of sep. form factors and structure factors and was used to model SAXS data recorded on dense samples. An advantage of the modeling method was that it made it possible to connect exptl. SAXS data to apparent average sizes of particles and cavities at different sample solid contents. Exptl. SAXS data could be modelled as a superposition of a limited number of simulated intensity components and gave results in qual. agreement with CP/MAS 13C-NMR data recorded on the same samples. For the water swollen samples, results obtained by the SAXS modeling method and results obtained from CP/MAS 13C-NMR measurements, agreed on the ranking of particle sizes in the different samples. The SAXS modeling method is dependent on simulations of autocorrelation functions. The time needed for simulations could be reduced by rescaling of simulated correlation functions, due to their independence of the choice of step size in real space. This way an autocorrelation function simulated for a specific sample could be used to generate SAXS intensity profiles corresponding to all length scales for that sample and used for efficient modeling of the exptl. data recorded on that sample.

  • 38.
    Li, Gen
    et al.
    KTH Royal Institute of Technology, Sweden.
    Varga, Imre
    Eötvös Loránd University, Hungary; University J. Selyeho, Slovakia.
    Kardos, Atilla
    Eötvös Loránd University, Hungary; University J. Selyeho, Slovakia.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden; Luleå University of Technology, Luleå.
    Claesson, Per M.
    RISE Research Institutes of Sweden. KTH Royal Institute of Technology, Sweden.
    Temperature-Dependent Nanomechanical Properties of Adsorbed Poly-NIPAm Microgel Particles Immersed in Water2021Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 37, nr 5, s. 1902-1912Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The temperature dependence of nanomechanical properties of adsorbed poly-NIPAm microgel particles prepared by a semibatch polymerization process was investigated in an aqueous environment via indentation-based atomic force microscopy (AFM) methods. Poly-NIPAm microgel particles prepared by the classical batch process were also characterized for comparison. The local mechanical properties were measured between 26 and 35 °C, i.e., in the temperature range of the volume transition. Two different AFM tips with different shapes and end radii were utilized. The nanomechanical properties measured by the two kinds of tips showed a similar temperature dependence of the nanomechanical properties, but the actual values were found to depend on the size of the tip. The results suggest that the semibatch synthesis process results in the formation of more homogeneous microgel particles than the classical batch method. The methodological approach reported in this work is generally applicable to soft surface characterization in situ.

  • 39.
    Li, Gen
    et al.
    KTH Royal Institute of Technology, Sweden.
    Varga, Imre
    Eötvös Loránd University, Hungary; University J. Selyeho, Slovakia.
    Kardos, Attila
    Eötvös Loránd University, Hungary; University J. Selyeho, Slovakia.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden; Luleå University of Technology, Sweden.
    Claesson, Per M.
    KTH Royal Institute of Technology, Sweden.
    Nanoscale Mechanical Properties of Core-Shell-like Poly-NIPAm Microgel Particles: Effect of Temperature and Cross-Linking Density.2021Ingår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, J Phys Chem B, Vol. 125, nr 34, s. 9860-9869Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Poly-NIPAm microgel particles with two different cross-linking densities were prepared with the classical batch polymerization process. These particles were adsorbed onto modified silica surfaces, and their nanomechanical properties were measured by means of atomic force microscopy. It was found that these particles have a hard core-soft shell structure both below and above the volume transition temperature. The core-shell-like structure appears due to a higher reaction rate of the cross-linker compared to that of the monomer, leading to depletion of cross-linker in the shell region. The microgel beads with lower average cross-linking density were found to be less stiff below the volume transition temperature than the microgel with higher cross-linking density. Increasing the temperature further to just above the volume transition temperature led to lower stiffness of the more highly cross-linked microgel compared to its less cross-linked counterpart. This effect is explained with the more gradual deswelling with temperature for the more cross-linked microgel particles. This phenomenon was confirmed by dynamic light scattering measurements in the bulk phase, which showed that the larger cross-linking density microgel showed a more gradual collapse in aqueous solution as the temperature was increased.

  • 40.
    Li, Hua
    et al.
    University of Newcastle, Australia.
    Somers, Anthony E.
    Deakin University, Australia.
    Howlett, Patrick C.
    Deakin University, Australia.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Forsyth, Maria
    Deakin University, Australia.
    Atkin, Rob
    University of Newcastle, Australia.
    Addition of low concentrations of an ionic liquid to a base oil reduces friction over multiple length scales: A combined nano- and macrotribology investigation2016Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, nr 9, s. 6541-6547Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The efficacy of ionic liquids (ILs) as lubricant additives to a model base oil has been probed at the nanoscale and macroscale as a function of IL concentration using the same materials. Silica surfaces lubricated with mixtures of the IL trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate and hexadecane are probed using atomic force microscopy (AFM) (nanoscale) and ball-on-disc tribometer (macroscale). At both length scales the pure IL is a much more effective lubricant than hexadecane. At the nanoscale, 2.0 mol% IL (and above) in hexadecane lubricates the silica as well as the pure IL due to the formation of a robust IL boundary layer that separates the sliding surfaces. At the macroscale the lubrication is highly load dependent; at low loads all the mixtures lubricate as effectively as the pure IL, whereas at higher loads rather high concentrations are required to provide IL like lubrication. Wear is also pronounced at high loads, for all cases except the pure IL, and a tribofilm is formed. Together, the nano- and macroscales results reveal that the IL is an effective lubricant additive - it reduces friction - in both the boundary regime at the nanoscale and mixed regime at the macroscale.

  • 41.
    Li, Hua
    et al.
    University of Newcastle, Australia.
    Somers, Anthony E.
    Deakin University, Australia.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Howlett, Patrick C.
    Deakin University, Australia.
    Atkin, Rob
    University of Newcastle, Australia.
    Combined nano- and macrotribology studies of titania lubrication using the oil-ionic liquid mixtures2016Ingår i: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 4, nr 9, s. 5005-5012Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The lubrication of titania surfaces using a series of ionic liquid (IL)-hexadecane mixtures has been probed using nanoscale atomic force microscopy (AFM) and macroscale ball-on-disk tribometer measurements. The IL investigated is trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate, which is miscible with hexadecane in all proportions. At both length scales, the pure IL is a much more effective lubricant than pure hexadecane. At low loads, which are comparable to common industrial applications, the pure IL reduces the friction by 80% compared to pure hexadecane; while the IL-hexadecane mixtures lubricate the titania surface as effectively as the pure IL and wear decreases with increasing IL concentration. At high test loads the adsorbed ion boundary layer is displaced leading to surface contact and high friction, and wear is pronounced for all IL concentrations. Nonetheless, the IL performs better than a traditional zinc-dialkyl-dithophosphate (ZDDP) antiwear additive at the same concentration.

  • 42.
    Li, Jing
    et al.
    KTH Royal Institute of Technology, Sweden.
    Huang, Hui
    KTH Royal Institute of Technology, Sweden.
    Fielden, Matthew
    KTH Royal Institute of Technology, Sweden.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Ecco, Luiz
    University of Trento, Italy.
    Schellbach, Carsten
    Enthone GmbH, Germany.
    Delmas, Grégory
    Arkema Coating Resins, France.
    Claesson, Per Martin
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. KTH Royal Institute of Technology, Sweden.
    Towards the mechanism of electrochemical activity and self-healing of 1 wt% PTSA doped polyaniline in alkyd composite polymer coating: Combined AFM-based studies2016Ingår i: RSC Advances, E-ISSN 2046-2069, Vol. 6, nr 23, s. 19111-19127Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A composite solvent-borne alkyd coating with 1 wt% p-toluene sulfonic acid (PTSA) doped polyaniline (PANI) was prepared. The mechanisms of electrochemical activity and self-healing properties of the composite coating were investigated by in situ atomic force microscopy (AFM), intermodulation AFM (ImAFM), electrochemical controlled (EC)-AFM combined with cyclic voltammetry (CV), Kelvin force microscopy (KFM), and Fourier transform infrared spectroscopy (FTIR), as well as open-circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) methods. The ImAFM demonstrates the multiphase structure of the composite coating and a high compatibility between the doped PANI and alkyd matrix. The CV and EC-AFM results reveal a high electrochemical activity of the doped PANI in the composite coating as well as reversible redox reactions between the emeraldine salt (ES) and leuco emeraldine base (LB) forms. The Volta potential mapping of KFM demonstrates a strong self-healing ability of the doped PANI in air conditions. The good electrochemical connection between the fine network of PANI in the composite coating and metal surface underneath enable the occurrence of reversible redox reaction between the ES/LB forms of doped PANI and a concomitant release of dopant anions both in air and in 3 wt% NaCl solution as demonstrated by OCP and EIS results. These therefore lead to the strong passivation and self-healing effect of the composite coated on the carbon steel surface.

  • 43.
    Li, Sichao
    et al.
    KTH Royal Institute of Technology, Sweden.
    Pilkington, Georgia A.
    KTH Royal Institute of Technology, Sweden.
    Mehler, Filip
    KTH Royal Institute of Technology, Sweden.
    Hammond, Oliver S.
    Stockholm University, Sweden; Aarhus University, Denmark.
    Boudier, Anthony
    Stockholm University, Sweden.
    Vorobiev, Alexei
    Uppsala University, Sweden.
    Glavatskih, Sergei
    KTH Royal Institute of Technology, Sweden; University of New South Wales, Australia; Ghent University, Belgium; .
    Rutland, Mark W.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. KTH Royal Institute of Technology, Sweden; University of New South Wales, Australia; École Centrale de Lyon, France.
    Tuneable interphase transitions in ionic liquid/carrier systems via voltage control2023Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 652, s. 1240-1249Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The structure and interaction of ionic liquids (ILs) influence their interfacial composition, and their arrangement (i.e., electric double-layer (EDL) structure), can be controlled by an electric field. Here, we employed a quartz crystal microbalance (QCM) to study the electrical response of two non-halogenated phosphonium orthoborate ILs, dissolved in a polar solvent at the interface. The response is influenced by the applied voltage, the structure of the ions, and the solvent polarizability. One IL showed anomalous electro-responsivity, suggesting a self-assembly bilayer structure of the IL cation at the gold interface, which transitions to a typical EDL structure at higher positive potential. Neutron reflectivity (NR) confirmed this interfacial structuring and compositional changes at the electrified gold surface. A cation-dominated self-assembly structure is observed for negative and neutral voltages, which abruptly transitions to an anion-rich interfacial layer at positive voltages. An interphase transition explains the electro-responsive behaviour of self-assembling IL/carrier systems, pertinent for ILs in advanced tribological and electrochemical contexts.

  • 44.
    Limbach, René
    et al.
    Friedrich Schiller University of Jena, Germany.
    Karlsson, Stefan
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Byggteknik.
    Scannell, Garth
    Friedrich Schiller University of Jena, Germany.
    Mathew, Renny
    Stockholm University, Sweden.
    Edén, Mattias
    Stockholm University, Sweden.
    Wondraczek, Lothar
    Friedrich Schiller University of Jena, Germany.
    The effect of TiO2 on the structure of Na2O-CaO-SiO2 glasses and its implications for thermal and mechanical properties2017Ingår i: Journal of Non-Crystalline Solids, ISSN 0022-3093, E-ISSN 1873-4812, Vol. 471, nr C, s. 6-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Titania represents an important compound for property modifications in the widespread family of soda lime silicate glasses. In particular, such titania-containing glasses offer interesting optical and mechanical properties, for example, for substituting lead-bearing consumer glasses. Here, we provide a systematic study of the effect of TiO2 on the structural, thermal, and mechanical properties for three series of quaternary Na2O–CaO–TiO2–SiO2 glasses with TiO2 concentrations up to 12 mol% and variable Na2O, CaO, and SiO2 contents. Structural analyses by Raman and magic-angle spinning 29Si NMR spectroscopy reveal the presence of predominantly four-fold coordinated Ti[4] atoms in glasses of low and moderate TiO2 concentrations, where Si–O–Si bonds are replaced by Si–O–Ti[4] bonds that form a network of interconnected TiO4 and SiO4 tetrahedra, with a majority of the non-bridging oxygen ions likely being located at the SiO4 tetrahedra. At higher TiO2 contents, TiO5 polyhedra are also formed. Incorporation of TiO2 strongly affects the titanosilicate network connectivity, especially when its addition is accompanied by a decrease of the CaO content. However, except for the thermal expansion coefficient, these silicate-network modifications seem to have no impact on the thermal and mechanical stability. Instead, the compositional dependence of the thermal and mechanical properties on the TiO2 content stems from its effect on the network energy and packing efficiency.

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  • 45.
    Lobov, Gleb S.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Zhao, Yichen
    KTH Royal Institute of Technology, Sweden.
    Marinins, Aleksandrs
    KTH Royal Institute of Technology, Sweden.
    Yan, Min
    KTH Royal Institute of Technology, Sweden.
    Li, Jiantong
    KTH Royal Institute of Technology, Sweden.
    Sugunan, Abhilash
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Thylén, Lars
    Hewlett-Packard Laboratories, US; KTH Royal Institute of Technology, Sweden.
    Wosinski, Lech
    KTH Royal Institute of Technology, Sweden.
    Östling, Mikael
    KTH Royal Institute of Technology, Sweden.
    Toprak, Muhammet S.
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Size impact of ordered P3HT nanofibers on optical anisotropy2016Ingår i: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 217, nr 9, s. 1089-1095Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Poly-3-hexylthiophene (P3HT) nanofibers are 1D crystalline structures with semiconductor properties. When P3HT nanofibers are dispersed in nonconducting solvent, they react to external alternate electric field by aligning along the field lines. This can be used to create layers of ordered nanofibers and is referred to as alternating current poling method. P3HT nanofibers with three different size distributions are fabricated, using self-assembly mechanism in marginal solvents, and used for the alignment studies. Anisotropic absorption of oriented 2 μm long nanofibers exponentially increases with the magnitude of applied field to a certain asymptotic limit at 0.8 V μm-1, while 100-500 nm long nanofibers respond to electric field negligibly. Effective optical birefringence of oriented 2 μm long nanofibers is calculated, based on the phase shift at 633 nm and the average layer thickness, to be 0.41. These results combined with further studies on real-time control over orientation of P3HT nanofibers in liquid solution or host system are promising in terms of exploiting them in electroabsorptive and electrorefractive applications.

  • 46.
    Lopez-Sanchez, Patricia
    et al.
    Chalmers University of Technology, Sweden.
    Assifaoui, Ali
    Université de Bourgogne Franche-Comté, Sweden.
    Cousin, Fabrice
    Université Paris-Saclay, France.
    Moser, Josefina
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Jordbruk och livsmedel.
    Bonilla, Mauricio
    Basque Center for Applied Mathematics, Spain.
    Ström, Anna
    Chalmers University of Technology, Sweden.
    Impact of Glucose on the Nanostructure and Mechanical Properties of Calcium-Alginate Hydrogels2022Ingår i: Gels, E-ISSN 2310-2861, Vol. 8, nr 2, artikel-id 71Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alginate is a polysaccharide obtained from brown seaweed that is widely used in food, pharmaceutical, and biotechnological applications due to its versatility as a viscosifier and gelling agent. Here, we investigated the influence of the addition of glucose on the structure and mechanical properties of alginate solutions and calcium-alginate hydrogels produced by internal gelation through crosslinking with Ca2+ . Using1H low-field nuclear magnetic resonance (NMR) and small angle neutron scattering (SANS), we showed that alginate solutions at 1 wt % present structural hetero-geneities at local scale whose size increases with glucose concentration (15–45 wt %). Remarkably, the molecular conformation of alginate in the gels obtained from internal gelation by Ca2+ crosslinking is similar to that found in solution. The mechanical properties of the gels evidence an increase in gel strength and elasticity upon the addition of glucose. The fitting of mechanical properties to a poroelastic model shows that structural changes within solutions prior to gelation and the increase in solvent viscosity contribute to the gel strength. The nanostructure of the gels (at local scale, i.e., up to few hundreds of Å) remains unaltered by the presence of glucose up to 30 wt %. At 45 wt %, the permeability obtained by the poroelastic model decreases, and the Young’s modulus increases. We suggest that macro (rather than micro) structural changes lead to this behavior due to the creation of a network of denser zones of chains at 45 wt % glucose. Our study paves the way for the design of calcium-alginate hydrogels with controlled structure for food and pharmaceutical applications in which interactions with glucose are of relevance. © 2022 by the authors.

  • 47.
    Lundgren, Anders
    et al.
    Chalmers University of Technology, Sweden.
    Munktell, Sara
    Uppsala University, Sweden.
    Lacey, Matthew
    Chalmers University of Technology, Sweden.
    Berglin, Mattias
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. University of Gothenburg, Sweden.
    Björefors, Fredrik
    Chalmers University of Technology, Sweden.
    Formation of gold nanoparticle size and density gradients via bipolar electrochemistry2016Ingår i: ChemElectroChem, E-ISSN 2196-0216, Vol. 3, nr 3, s. 378-382Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bipolar electrochemistry is employed to demonstrate the formation of gold nanoparticle size gradients on planar surfaces. By controlling the electric field in a HAuCl4-containing electrolyte, gold was reduced onto 10nm diameter particles immobilized on pre-modified thiolated bipolar electrode (BPE) templates, resulting in larger particles towards the more cathodic direction. As the gold deposition was the dominating cathodic reaction, the increased size of the nanoparticles also reflected the current distribution on the bipolar electrode. The size gradients were also combined with a second gradient-forming technique to establish nanoparticle surfaces with orthogonal size and density gradients, resulting in a wide range of combinations of small/large and few/many particles on a single bipolar electrode. Such surfaces are valuable in, for example, cell-material interaction and combinatorial studies, where a large number of conditions are probed simultaneously.

  • 48.
    Matougui, Nada
    et al.
    Inserm, France.
    Boge, Lukas
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Groo, Anne-Claire
    Inserm, France.
    Umerska, Anita
    Inserm, France.
    Ringstad, Lovisa
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Bysell, Helena
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Saulnier, Patrick
    Inserm, France; CHU Angers, France.
    Lipid-based nanoformulations for peptide delivery2016Ingår i: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 502, nr 1-2, s. 80-97Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Nanoformulations have attracted a lot of attention because of their size-dependent properties. Among the array of nanoformulations, lipid nanoformulations (LNFs) have evoked increasing interest because of the advantages of their high degree of biocompatibility and versatility. The performance of lipid nanoformulations is greatly influenced by their composition and structure. Therapeutic peptides represent a growing share of the pharmaceutical market. However, the main challenge for their development into commercial products is their inherent physicochemical and biological instability. Important peptides such as insulin, calcitonin and cyclosporin A have been incorporated into LNFs. The association or encapsulation of peptides within lipid-based carriers has shown to protect the labile molecules against enzymatic degradation. This review describes strategies used for the formulation of peptides and some methods used for the assessment of association efficiency. The advantages and drawbacks of such carriers are also described.

  • 49.
    Medina, Enrique
    et al.
    Alliance Consulting International, US.
    Wellon, George C.
    Wellon Safety Solutions Inc., Canada.
    Evegren, Franz
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Methanol Safe Handling Manual: 4th Edition2017Rapport (Övrigt vetenskapligt)
  • 50.
    Michel, Bastien
    et al.
    University Grenoble Alpes, France.
    Heggset, Ellinor B
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Syverud, Kristin
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. NTNU, Norway.
    Dufresne, Alain
    University Grenoble Alpes, France.
    Bras, Julien
    University Grenoble Alpes, France.
    Inclusion complex formation between sulfadiazine and various modified β-cyclodextrins and characterization of the complexes2022Ingår i: Journal of Drug Delivery Science and Technology, ISSN 1773-2247, Vol. 76, artikel-id 103814Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    β-Cyclodextrin (β-CD) and its derivatives are cyclic oligosaccharides which present the ability to form inclusion complexes with hydrophobic molecules and can bring new functionalities to a wide range of materials. As of today, the most used prophylactic drugs for wound dressing applications are sulfadiazine (SD) and its derivatives silver sulfadiazine (SSD). These drugs are used to prevent infections of the wounds; however, their low intrinsic water-solubility is a hindrance to their use. In this study, the inclusion complex formation between SD/SSD and the various β-CDs were assessed with various protocols. Isothermal Titration Calorimetry (ITC) experiments led to the conclusion that the formation constants measured for SD and SSD are sufficiently similar meaning that SD can be considered as a satisfactory model molecule. Phase Solubility Diagram (PSD) were built for SD and the various β-CDs, highlighting a 1:1 stoichiometry of inclusion and a linear increase in solubility of SD with increasing concentration of β-CDs- The formation constant ranged from 197 M−1 to 245 M−1 for the different β-CDs. X-Ray diffraction (XRD) and Differential Scanning Calorimetry (DSC) experiments revealed the different physico-chemical properties affected by the formation of an inclusion complex. Finally, Nuclear Magnetic Resonance (NMR) experiments confirmed the depth of penetration of SD inside the β-CDs cavity as well as the orientation of SD, highlighting the fact that CM-β-CDs induce a deeper penetration than other β-CDs.

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