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  • 1.
    Abitbol, Tiffany
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Alvarez-Asencio, Ruben
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Swerin, Agne
    KTH Royal Institute of Technology, Sweden.
    Nanocellulose-Based Hybrid Materials for UV Blocking and Mechanically Robust Barriers2020In: ACS Applied Bio Materials, E-ISSN 2576-6422, Vol. 3, no 4, p. 2245-2254Article in journal (Refereed)
    Abstract [en]

    Nanocellulose (NC)-based hybrid coatings and films containing CeO2 and SiO2 nanoparticles (NPs) to impart UV screening and hardness properties, respectively, were prepared by solvent casting. The NC film-forming component (75 wt % of the overall solids) was composed entirely of cellulose nanocrystals (CNCs) or of CNCs combined with cellulose nanofibrils (CNFs). Zeta potential measurements indicated that the four NP types (CNC, CNF, CeO2, and SiO2) were stably dispersed in water and negatively charged at pH values between 6 and 9. The combination of NPs within this pH range ensured uniform formulations and homogeneous coatings and films, which blocked UV light, the extent of which depended on film thickness and CeO2 NP content, while maintaining good transparency in the visible spectrum (∼80%). The addition of a low amount of CNFs (1%) reduced the film hardness, but this effect was compensated by the addition of SiO2 NPs. Chiral nematic self-assembly was observed in the mixed NC film; however, this ordering was disrupted by the addition of the oxide NPs. The roughness of the hybrid coatings was reduced by the inclusion of oxide NPs into the NC matrix perhaps because the spherical oxide NPs were able to pack into the spaces between cellulose fibrils. We envision these hybrid coatings and films in barrier applications, photovoltaics, cosmetic formulations, such as sunscreens, and for the care and maintenance of wood and glass surfaces, or other surfaces that require a smooth, hard, and transparent finish and protection from UV damage.

  • 2.
    Abitbol, Tiffany
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation.
    Swerin, Agne
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation.
    UV-blocking hybrid nanocellulose films containing ceria and silica nanoparticles2018In: International Conference on Nanotechnology for Renewable Materials 2018, 2018, p. 503-515Conference paper (Refereed)
  • 3.
    Ahniyaz, Anwar
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    de Meatza, Iratxe
    CIDETEC, Spain.
    Kvasha, Andriy
    CIDETEC, Spain.
    Garcia-Calvo, Oihane
    CIDETEC, Spain.
    Ahmed, Istaq
    Volvo Group Trucks Technology, Sweden.
    Sgroi, Mauro Francesco
    C.R.F. S.C.p.A, Italy.
    Giuliano, Mattia
    C.R.F. S.C.p.A, Italy.
    Dotoli, Matteo
    C.R.F. S.C.p.A, Italy.
    Dumitrescu, Mihaela-Aneta
    Faam Research Center, Italy.
    Jahn, Marcus
    AIT, Austria.
    Zhang, Ningxin
    AIT, Austria.
    Progress in solid-state high voltage lithium-ion battery electrolytes2021In: Advances in Applied Energy, ISSN 2666-7924, Vol. 4, article id 100070Article in journal (Refereed)
    Abstract [en]

    Developing high specific energy Lithium-ion (Li-ion) batteries is of vital importance to boost the production of efficient electric vehicles able to meet the customers’ expectation related to the electric range of the vehicle. One possible pathway to high specific energy is to increase the operating voltage of the Li-ion cell. Cathode materials enabling operation above 4.2 V are available. The stability of the positive electrode-electrolyte interface is still the main bottleneck to develop high voltage cells. Moreover, important research efforts are devoted to the substitution of graphite anodes with Li metal: this would improve the energy density of the cell dramatically. The use of metallic lithium is prevented by the dendrite growth during charge, with consequent safety problems. To suppress the formation of dendrites solid-state electrolytes are considered the most promising approach. For these reasons the present review summarizes the most recent research efforts in the field of high voltage solid-state electrolytes for high energy density Li-ion cells.

  • 4.
    Alvarez-Asencio, Ruben
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials.
    Corkery, Robert W.
    KTH Royal Institute of Technology, Sweden.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials.
    Solventless synthesis of cerium oxide nanoparticles and their application in UV protective clear coatings2020In: RSC Advances, E-ISSN 2046-2069, Vol. 10, no 25, p. 14818-14825Article in journal (Refereed)
    Abstract [en]

    Colloidal dispersions of cerium oxide nanoparticles are of importance for numerous applications including as catalysts, chemical mechanical polishing agents and additives for UV protective and anticorrosion coatings. Here, concentrated oleate-coated cerium oxide nanoparticles (CeO2 NPs) with a uniform size have been produced by solventless thermolysis of cerium-oleate powder under low pressure at 320 °C and subsequently dispersed in hexane. Unlike any previously reported colloidal synthesis process for ceria nanoparticles, this process does not involve any toxic high boiling point organic solvent that requires subsequent removal at high cost. Although the process is very simple, highly concentrated cerium oxide nanoparticles with more than 17 wt% solid content and 70% of the theoretical yield can be easily obtained. Moreover, the size, shape and crystallinity of cerium oxide nanoparticles can be tailored by changing the thermal decomposition temperature and reaction time. Moreover, the new synthesis route developed in this study allows the synthesis of clean and dispersible ceria nanoparticles at a relatively low cost in a single step. The prepared ceria nanoparticles have an excellent UV absorption property and remain transparent to visible light, thus having the potential to replace potentially hazardous organic compounds in UV absorbing clear coatings. As a proof of concept, the prepared dispersions of cerium oxide nanoparticles in hexane were formulated into a solvent borne binder base to develop clear UV protecting coatings for light sensitive substrates. The general synthesis strategy presented in this study is generally applicable for the low-cost production of a concentrated dispersion of metal oxide nanoparticles with minimal environmental impact.

  • 5.
    Bardage, Stig
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP Trä.
    Henriksson, Marielle
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP Trä.
    Olsson, Sara
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP Trä.
    Collins, Peter
    Meng, Decheng
    Ahniyaz, Anwar
    Johansson Salazar-Sandoval, Eric
    Rahnier, André
    Gasparini, Michèle
    Lamproye, Nicolas
    Nanoparticles for UV Protection of Clear Coatings – Field and Laboratory Trials2013In: Surface Coatings International (SCI), ISSN 1754-0925, Vol. 96, no 2, p. 94-99Article in journal (Refereed)
  • 6.
    Booth, Andy
    et al.
    SINTEF, Norway.
    Størseth, Trond
    SINTEF, Norway.
    Altin, Dag
    BioTrix, Norway.
    Fornara, Andrea
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Jungnickel, Harald
    BfR German Federal Institute for Risk Assessment, Germany.
    Laux, Peter
    BfR German Federal Institute for Risk Assessment, Germany.
    Luch, Andreas
    BfR German Federal Institute for Risk Assessment, Germany.
    Sørensen, Lisbet
    SINTEF, Norway.
    Freshwater dispersion stability of PAA-stabilised cerium oxide nanoparticles and toxicity towards Pseudokirchneriella subcapitata2015In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 505, p. 596-605Article in journal (Refereed)
    Abstract [en]

    An aqueous dispersion of poly (acrylic acid)-stabilised cerium oxide (CeO2) nanoparticles (PAA-CeO2) was evaluated for its stability in a range of freshwater ecotoxicity media (MHRW, TG 201 and M7), with and without natural organic matter (NOM). In a 15day dispersion stability study, PAA-CeO2 did not undergo significant aggregation in any media type. Zeta potential varied between media types and was influenced by PAA-CeO2 concentration, but remained constant over 15days. NOM had no influence on PAA-CeO2 aggregation or zeta potential. The ecotoxicity of the PAA-CeO2 dispersion was investigated in 72h algal growth inhibition tests using the freshwater microalgae Pseudokirchneriella subcapitata. PAA-CeO2 EC50 values for growth inhibition (GI; 0.024mg/L) were 2-3 orders of magnitude lower than pristine CeO2 EC50 values reported in the literature. The concentration of dissolved cerium (Ce3+/Ce4+) in PAA-CeO2 exposure suspensions was very low, ranging between 0.5 and 5.6μg/L. Free PAA concentration in the exposure solutions (0.0096-0.0384mg/L) was significantly lower than the EC10 growth inhibition (47.7mg/L) value of pure PAA, indicating that free PAA did not contribute to the observed toxicity. Elemental analysis indicated that up to 38% of the total Cerium becomes directly associated with the algal cells during the 72h exposure. TOF-SIMS analysis of algal cell wall compounds indicated three different modes of action, including a significant oxidative stress response to PAA-CeO2 exposure. In contrast to pristine CeO2 nanoparticles, which rapidly aggregate in standard ecotoxicity media, PAA-stabilised CeO2 nanoparticles remain dispersed and available to water column species. Interaction of PAA with cell wall components, which could be responsible for the observed biomarker alterations, could not be excluded. This study indicates that the increased dispersion stability of PAA-CeO2 leads to an increase in toxicity compared to pristine non-stabilised forms.

  • 7.
    Dobryden, Illia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Montanari, Celine
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Bhattacharjya, DHRUBAJYOTI
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Aydin, Juhanes
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Bio-Based Binder Development for Lithium-Ion Batteries.2023In: Materials, E-ISSN 1996-1944, Vol. 16, no 16, article id 5553Article in journal (Refereed)
    Abstract [en]

    The development of rechargeable lithium-ion battery (LIB) technology has facilitated the shift toward electric vehicles and grid storage solutions. This technology is currently undergoing significant development to meet industrial applications for portable electronics and provide our society with "greener" electricity. The large increase in LIB production following the growing demand from the automotive sector has led to the establishment of gigafactories worldwide, thus increasing the substantial consumption of fossil-based and non-sustainable materials, such as polyvinylidene fluoride and/or styrene-butadiene rubber as binders in cathode and anode formulations. Furthermore, the use of raw resources, such as Li, Ni, and Mn in cathode active materials and graphite and nanosilicon in anodes, necessitates further efforts to enhance battery efficiency. To foster a global sustainable transition in LIB manufacturing and reduce reliance on non-sustainable materials, the implementation of bio-based binder solutions for electrodes in LIBs is crucial. Bio-based binders such as cellulose, lignin, alginate, gums, starch, and others can address environmental concerns and can enhance LIBs' performance. This review aims to provide an overview of the current progress in the development and application of bio-based binders for LIB electrode manufacturing, highlighting their significance toward sustainable development.

  • 8.
    Ecco, Luiz Gustavo
    et al.
    University of Trento, Italy.
    Fedel, Michele
    University of Trento, Italy.
    Ahniyaz, Anwar
    Deflorian, Flavio
    University of Trento, Italy.
    Influence of polyaniline and cerium oxide nanoparticles on the corrosion protection properties of alkyd coating2014In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 77, no 12, p. 2031-2038Article in journal (Refereed)
    Abstract [en]

    A study of the anticorrosive properties of an alkyd coating loaded with polyaniline and cerium oxide (CeO2) nanoparticles is presented in this paper. Investigated by means of Electrochemical Impedance Spectroscopy and accelerated salt spray test, the blank alkyd coating has been loaded with PAni, ceria nanoparticles and the combination of both with 1.0 wt.% content. Through the monitoring of open circuit potential, an ennoblement effect was detected for the systems in the presence of a mild solution. Moreover, EIS evolution of the alkyd containing polyaniline revealed a stable performance of the system in the presence of sulphate solution, whereas for those containing ceria nanoparticles a considerable raise in the |Z|0.015 Hz, from 107 to 108 Ω cm2 in the course of 24 h of immersion, an increasing trend of the charge transfer resistance during the equivalent period of exposure was observed. Furthermore, the anticorrosive contribution given by the ceria nanoparticlesis supported by the accelerated salt spray test which revealed lower delamination rates. In the case of the alkyd loaded with polyaniline and ceria nanoparticles simultaneously the evidences are less perceived by means of electrochemical analysis, however, from salt spray tests it can be seen that the influence of the mixture is promising at a certain extent.

  • 9.
    Faure, Bertrand
    et al.
    Stockholm University, Sweden.
    Salazar-Alvarez, German
    Stockholm University, Sweden.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Villaluenga, Irune
    TECNALIA, Spain.
    Berriozabal, Gemma
    TECNALIA, Spain.
    De Miguel, Yolanda R.
    TECNALIA, Spain.
    Bergström, Lennart
    Stockholm University, Sweden.
    Dispersion and surface functionalization of oxide nanoparticles for transparent photocatalytic and UV-protecting coatings and sunscreens2013In: Science and Technology of Advanced Materials, ISSN 1468-6996, E-ISSN 1878-5514, Vol. 14, no 2, article id 23001Article in journal (Refereed)
    Abstract [en]

    This review describes recent efforts on the synthesis, dispersion and surface functionalization of the three dominating oxide nanoparticles used for photocatalytic, UV-blocking and sunscreen applications: titania, zinc oxide, and ceria. The gas phase and liquid phase synthesis is described briefly and examples are given of how weakly aggregated photocatalytic or UV-absorbing oxide nanoparticles with different composition, morphology and size can be generated. The principles of deagglomeration are reviewed and the specific challenges for nanoparticles highlighted. The stabilization of oxide nanoparticles in both aqueous and non-aqueous media requires a good understanding of the magnitude of the interparticle forces and the surface chemistry of the materials. Quantitative estimates of the Hamaker constants in various media and measurements of the isoelectric points for the different oxide nanoparticles are presented together with an overview of different additives used to prepare stable dispersions. The structural and chemical requirements and the various routes to produce transparent photocatalytic and nanoparticle-based UV-protecting coatings, and UV-blocking sunscreens are described and discussed.

  • 10.
    Fedel, Michele
    et al.
    University of Trento, Italy.
    Ahniyaz, Anwar
    Ecco, Luiz Gustavo
    University of Trento, Italy.
    Deflorian, Flavio
    University of Trento, Italy.
    Electrochemical investigation of the inhibition effect of CeO2 nanoparticles on the corrosion of mild steel2014In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 131, no Jun, p. 71-78Article in journal (Refereed)
    Abstract [en]

    The paper aims to provide some insight into the fundamental mechanisms for the behavior of cerium oxides nanoparticles as corrosion inhibitors for steel. The work was carried out on mild steel water based dispersions of cerium oxides nanoparticles in presence of both, sulfates and chlorides. Ceria nanoparticles were produced via precipitation of cerium Ce(NO3)3.6H 2O in water, particles of about 70 nm hydrodynamic diameter were obtained. The analysis of the effectiveness of the ceria nanoparticles as corrosion inhibitors was performed by means of electrochemicaltechniques such as electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) versus time measurements. The experimental measurements suggested that cerium oxide affects the electrochemical properties of mild steel surface; they promoted an ennoblement effect and strong modifications in the impedance response.

  • 11.
    He, Yunjuan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Boluk, Yaman
    University of Alberta, Canada.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation.
    Deltin, Tomas
    PTE Coatings AB, Sweden.
    Claesson, Per M
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Comparative study of CNC and CNF as additives in waterborne acrylate-based anti-corrosion coatings2019In: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351, Vol. 41, no 13, p. 2037-2047Article in journal (Refereed)
    Abstract [en]

    Nanocomposite coatings are of great interest as barrier coatings since synergy effects between matrix and additive properties can be achieved. This, however, requires favorable additive-matrix interactions to provide a strong interphase (interface region). In this work we elucidate the properties of two environmentally benign nanocomposite coatings based on a waterborne acrylate formulation with additives from renewable sources, i.e. either cellulose nanocrystals, CNC; or, alternatively, cellulose nanofibrils, CNF. We focus on the corrosion protective properties of these coatings and discuss the reason why the nanocomposite with CNC displays favorable corrosion protection properties whereas that with CNF does not. To this end we utilized scanning electron microscopy, water contact angle measurement, Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy techniques to investigate the microstructure, surface wetting, interactions between cellulosic materials and matrix as well as corrosion protective properties of both composite coatings.

  • 12.
    He, Yunjuan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Boluk, Yaman
    University of Alberta, Canada.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Deltin, Tomas
    PTE Coatings AB, Sweden.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Corrosion protective properties of cellulose nanocrystals reinforced waterborne acrylate-based composite coating2019In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 155, p. 186-194Article in journal (Refereed)
    Abstract [en]

    The present investigation highlights corrosion protection of carbon steel by a waterborne acrylate-based matrix coating, with and without reinforcement by cellulose nanocrystals, by using electrochemical impedance spectroscopy in 0.1 M NaCl solution over a period of 35 days. Interactions between cellulose nanocrystals and the matrix coating were demonstrated by Fourier transform infrared spectroscopy. The results show that both coatings have high barrier performance but different protective characteristics during long-term exposure. The differences can be attributed to the reinforcement effect of cellulose nanocrystals caused by hydrogen bonding interactions between cellulose nanocrystals and the matrix coating.

  • 13.
    He, Yunjuan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation.
    Deltin, Tomas
    PTE Coatings AB, Sweden.
    Corkery, Robert W.
    KTH Royal Institute of Technology, Sweden.
    Claesson, Per M.
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Nano-scale mechanical and wear properties of a waterborne hydroxyacrylic-melamine anti-corrosion coating2018In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 457, p. 548-558Article in journal (Refereed)
    Abstract [en]

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

  • 14.
    Johansson Salazar-Sandoval, Eric
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Radical initiator modified cerium oxide nanoparticles for polymer encapsulation via grafting from the surface2014In: RSC Advances, E-ISSN 2046-2069, Vol. 4, no 106, p. 61863-61868Article in journal (Refereed)
    Abstract [en]

    The present paper describes a versatile route to modify and stabilize ceria nanoparticles with a radical initiator, 4,4′-azobis(4-cyanovaleric acid) (ACVA), allowing a strong interface to be formed via grafting of polymers from the surface. This leads to the successful encapsulation of cerium oxide nanoparticles in a poly(methyl methacrylate) matrix. The interaction between the radical initiator and the surface of ceria is studied by FTIR spectroscopy where a consistent shift of the carboxylate band unequivocally demonstrates that the carboxylate groups of this acidic initiatorcomplex the cerium ions on the ceria surface by means of strong and stable ionic bonding.

  • 15.
    Johansson Salazar-Sandoval, Eric
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor. KTH Royal Institute of Technology, Sweden.
    Johansson, M. K. G.
    KTH Royal Institute of Technology, Sweden.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Aminopolycarboxylic acids as a versatile tool to stabilize ceria nanoparticles-a fundamental model experimentally demonstrated2014In: RSC Advances, E-ISSN 2046-2069, Vol. 4, no 18, p. 9048-9055Article in journal (Refereed)
    Abstract [en]

    An extremely stable water dispersion of cerium oxide nanoparticles was prepared by colloidal synthesis, using nitrilotriacetic acid (NTA) as a stabilizer. Based on FT-IR measurements, the surface characteristics of NTA-stabilized ceria nanoparticles are clarified and a fundamental stabilization mechanism is proposed. The mechanism is based on the combination of the ionic nature of cerium oxide surface and the inner-sphere complexation model. From an application perspective it is remarkable that ceria nanoparticle dispersions stabilized by NTA are stable at neutral pH, which makes them a potential successful additive in UV screening applications.

  • 16.
    Karpenja, Tatjana
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. Digital Cellulose Center, Sweden.
    Granberg, Hjalmar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. Digital Cellulose Center, Sweden.
    Edberg, Jesper
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware. Digital Cellulose Center, Sweden.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Circularity of DCC materials – case study on three energy storage solutions2022Report (Other academic)
    Abstract [en]

    Due to growing concerns about the environmental impacts of fossil fuels and the capacity and resilience of energy grids around the world, engineers and policymakers are increasingly turning their attention to energy storage solutions1. In turn, the huge demand for materials for such storage systems will require a considerable energy input in extraction, processing and materials formulation, and new and sustainable electrochemical systems need to be developed2. Current report is the result of the exploration work where the circularity and environmental potentials of biobased energy storage solutions were analysed in the form of iterative interviews with stakeholders along the energy storage and packaging value chains, complemented by literature research. The work was performed within the scope of Digital Cellulose Center (DCC) research center3 in the sub-project 1 “Circularity of DCC materials” of the Theme 1: Design for a circular bioeconomy. Totally three systems were selected and analysed in the form of three respective case studies: • Case study I: Biobased battery (Chemical energy storage system) • Case study II: Biobased printed supercapacitor (Electrochemical energy storage system) • Case study III: Intelligent packaging (Chemical or electrochemical energy storage for fiber-based packaging) Each case study was put into the life cycle context where aspects such as legislation, circularity potential and potential environmental impact were discovered. The biobased battery for large-scale grid storage applications was classified as an industrial battery with collection rate requirement of 75% at end-of-life, of which 50% to be materially recycled. The biobased printed supercapacitor was classified as an electric and electronic equipment (EEE) with collection rate requirement of 65%, of which recovery and recycling / preparing for reuse targets vary between 55% - 85% depending on application. The material recycling target for the fiber-based intelligent packaging is 85% since being perceived as a paper-based packaging it would enter paper packaging recycling stream rather than entering the recycling stream of Waste electrical and electronic equipment (WEEE). In next steps of this exploratory journey, the compositions of the respective energy storage solutions were identified, including biobased content and recycling potential on the short- and long-term, compared to their benchmark solutions where possible. Today, the material recycling processes for batteries and WEEE are strongly economically driven: the material components that are considered as valuable by recyclers are mainly base metals (e.g., aluminium, steel) and to low extent critical raw materials (e.g., cobalt, nickel). The biobased energy storage solutions though do not contain any critical raw materials and use base metals to a less extent. This is a dilemma where the material value of the biobased, renewable materials (more sustainable materials by origin) is not favourable in the end-of-life processes of today and therefore will be lost (i.e., incinerated). A more balanced approach to such dilemma is urged in order to facilitate both economic and environmental incentives in the energy storage value cycles. Current Battery and WEEE directives do not promote the recycling of materials that are critical or have a high environmental burden, which in practice results in loss of those materials, not least due to lack of economy in recycling processes. Moreover, the legislation needs to be adapted in order to meet innovative development in the area. It can be relevant to introduce a cross-sectoral category ‘Biobased energy storage solutions’ in the upcoming legislation with the aim to encourage use of more abundant, biobased materials and thus decouple energy storage applications from use of critical raw materials.

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  • 17.
    Kohs, Wolfram
    et al.
    AIT Austrian Institute of Technology, Austria.
    Kahr, Jurgen
    AIT Austrian Institute of Technology, Austria.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Chemistry and Materials.
    Zhang, Ningxin
    AIT Austrian Institute of Technology, Austria.
    Trifonova, Atanaska
    AIT Austrian Institute of Technology, Austria.
    Electrolyte-cathode interactions in 5-V lithium-ion cells2017In: Journal of Solid State Electrochemistry, ISSN 1432-8488, E-ISSN 1433-0768, Vol. 21, no 12, p. 3389-3401Article in journal (Refereed)
    Abstract [en]

    The electrolyte/electrode interactions on the anode side of a lithium-ion cell and the formation of the solid electrolyte interphase (SEI) have been investigated intensively in the past and are fairly well understood. Present knowledge about the reactions on the cathode side and the resulting cathode electrolyte interphase (CEI) is less detailed. In this study, the electrolyte/electrode interactions on the surface of the high-voltage cathode material LiNi0.5Mn1.5O4 (LNMO), both bare and FePO4-coated, were investigated. The gases evolving upon first time charging of the system were investigated using a GC/MS combination. The degradation products included THF, dimethyl peroxide, phosphor trifluoride, 1,3-dioxolane and dimethyl difluor silane, formed in the GC’s column as its coating reacts with HF from the experiments. Although these substances and their formation are in themselves interesting, the absence of many degradation products which have been mentioned in the existing literature is of equal interest. Our results clearly indicate that coating a cathode material can have a major influence on the amount and composition of the gaseous decomposition products in the formation phase.

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  • 18.
    Li, Jing
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ecco, Luiz
    University of Trento, Italy.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Fedel, Michele
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    In situ AFM and electrochemical study of a waterborne acrylic composite coating with CeO2 nanoparticles for corrosion protection of carbon steel2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 10, p. C610-C618Article in journal (Refereed)
    Abstract [en]

    The corrosion protection of a waterborne acrylic composite coating with 1 wt% ceria nanoparticles (CeNP) coated on carbon steel in 3 wt% NaCl solution was investigated by ex-situ and in situ as well as electrochemical atomic force microscopy (AFM) observations, combined with open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The synthesized CeNP were stabilized by acetic acid. The transmission electron microscopy characterization showed fine nano-size of as-synthesized CeNP, the ex-situ AFM imaging revealed uniform dispersion of the CeNP in the composite coating and greatly reduced nano-sized pinholes in the coating. The in situ and electrochemical (EC) AFM investigations indicate release of some CeNP and aggregates from the coating surface and then precipitation of some particles and cerium-compounds during the exposure. The OCP and EIS results demonstrated that the addition of 1 wt% CeNP leads to a significantly improved long term barrier type corrosion protection of the waterborne acrylic composite coating for carbon steel in 3 wt% NaCl solution. The beneficial effect of the CeNP is attributed to the blocking of nano-sized defects and inhibition by the cerium compounds originated from the acetic acid stabilized CeNP.

  • 19.
    Li, Jing.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ecco, Luiz
    University of Trento, Italy.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Pan, Jinshan
    KTH Royal Institute of Technology, School .
    Probing electrochemical mechanism of polyaniline and CeO 2 nanoparticles in alkyd coating with in-situ electrochemical-AFM and IRAS2019In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 132, p. 399-408Article in journal (Refereed)
    Abstract [en]

    The corrosion protection and electrochemical mechanism of solvent-borne alkyd composite coating containing 1.0 wt.% polyaniline (PANI) and 1.0 wt.% CeO 2 nanoparticles (NPs) for carbon steel in 3.0 wt.% NaCl solution were investigated by means of scanning electron microscopy (SEM), ex-situ, in-situ and electrochemical controlled (EC) atomic force microscopy (AFM), open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) methods. The SEM and ex-situ AFM results revealed the micro- and nanostructure of the composite coating. The in-situ sequential AFM images and line profiling analysis indicated electrochemical activity of the NPs and a high stability of the composite coating in NaCl solution. The results of EC-AFM combined with cyclic voltammetry (CV) demonstrated volume change of the PANI NPs upon reduction and oxidation at certain applied potentials on the coating. The redox reactions between the different forms of PANI and the effect of the CeO 2 NPs on the polymerization of the composite polymer were further confirmed by infrared reflection absorption spectroscopy (IRAS). The OCP and EIS results revealed that the composite coating provided an improved corrosion protection for carbon steel within several days of exposure, which was attributed to the barrier protection of CeO 2 NPs and the passivation ability of PANI.

  • 20.
    Li, Shanghua
    et al.
    ABB, Sweden.
    Karlsson, Mattias
    ABB, Sweden.
    Liu, Rongsheng
    ABB, Sweden.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Fornara, Andrea
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Johansson Salazar-Sandoval, Eric
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    The effect of ceria nanoparticles on the breakdown strength of transformer oil2015In: 2015 IEEE 11th International Conference on the Properties and Applications of Dielectric Materials (ICPADM), Institute of Electrical and Electronics Engineers (IEEE), 2015, p. 289-292Conference paper (Refereed)
    Abstract [en]

    Nanotechnologies have potential to be used in transformer industry in enhancing material properties which may lead to a compact design of transformer and reduced manufacturing cost. Effect of adding different nanoparticles such as titania, silica, nano-diamond, etc. has been studied in literatures. In this paper, nano-ceria particles have been successfully added into transformer mineral oil with different content. The suspension is very stable and no segmentation can be observed over several months. The ceria nanoparticles are commercially available, which have a quite narrow size distribution. UV-Vis, TGA and FT-IR are used to characterize the ceria nanofluids. The water content of the ceria nanofluids has been measured by Karl Fisher titration, which is important for the breakdown strength of transformer oil. AC voltage breakdown and lightning impulse voltage breakdown measurements have been performed on the ceria nanofluids. An enhancement of 15% on AC breakdown voltage has been observed on ceria nanofluids with some content compared to reference transformer oil. On the other hand, no clear difference on the lightning impulse breakdown voltage is observed between the ceria nanofluids and reference transformer oil.

  • 21.
    Majee, Subimal
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Zhao, Wei
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. Uppsala University, Sweden.
    Sugunan, Abhilash
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Gillgren, .T
    BillerudKorsnäs AB, Sweden.
    Larsson, J. A.
    BillerudKorsnäs AB, Sweden.
    Brooke, Robert
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Nordgren, Niklas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Zhang, Z. -B
    Uppsala University, Sweden.
    Zhang, S. -L
    Uppsala University, Sweden.
    Nilsson, David
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Highly Conductive Films by Rapid Photonic Annealing of Inkjet Printable Starch–Graphene Ink2021In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 9, no 5, article id 2101884Article in journal (Refereed)
    Abstract [en]

    A general formulation engineering method is adopted in this study to produce a highly concentrated (≈3 mg mL−1) inkjet printable starch–graphene ink in aqueous media. Photonic annealing of the starch–graphene ink is validated for rapid post-processing of printed films. The experimental results demonstrate the role of starch as dispersing agent for graphene in water and photonic pulse energy in enhancing the electrical properties of the printed graphene patterns, thus leading to an electrical conductivity of ≈2.4 × 104 S m−1. The curing mechanism is discussed based on systematic material studies. The eco-friendly and cost-efficient approach presented in this work is of technical potential for the scalable production and integration of conductive graphene inks for widespread applications in printed and flexible electronics. 

  • 22.
    Orr, Mark
    et al.
    Infectious Disease Research Institute, US; University of Washington, US.
    Khandhar, Amit
    Infectious Disease Research Institute, US.
    Seydoux, Emilie
    Infectious Disease Research Institute, US.
    Liang, Hong
    Infectious Disease Research Institute, US.
    Gage, Emily
    Infectious Disease Research Institute, US.
    Mikasa, Tracie
    Infectious Disease Research Institute, US.
    Beebe, Elyse
    Infectious Disease Research Institute, US.
    Rintala, Nicholas
    Infectious Disease Research Institute, US.
    Persson, Karin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Carter, Darrick
    Infectious Disease Research Institute, US.
    Reed, Steven
    Infectious Disease Research Institute, US.
    Fox, Christopher
    Infectious Disease Research Institute, US; University of Washington, US.
    Reprogramming the adjuvant properties of aluminum oxyhydroxide with nanoparticle technology2019In: npj Vaccines, ISSN 2059-0105, Vol. 4, article id 1Article in journal (Refereed)
    Abstract [en]

    Aluminum salts, developed almost a century ago, remain the most commonly used adjuvant for licensed human vaccines. Compared to more recently developed vaccine adjuvants, aluminum adjuvants such as Alhydrogel are heterogeneous in nature, consisting of 1–10 micrometer-sized aggregates of nanoparticle aluminum oxyhydroxide fibers. To determine whether the particle size and aggregated state of aluminum oxyhydroxide affects its adjuvant activity, we developed a scalable, top-down process to produce stable nanoparticles (nanoalum) from the clinical adjuvant Alhydrogel by including poly(acrylic acid) (PAA) polymer as a stabilizing agent. Surprisingly, the PAA:nanoalum adjuvant elicited a robust TH1 immune response characterized by antigen-specific CD4+ T cells expressing IFN-γ and TNF, as well as high IgG2 titers, whereas the parent Alhydrogel and PAA elicited modest TH2 immunity characterized by IgG1 antibodies. ASC, NLRP3 and the IL-18R were all essential for TH1 induction, indicating an essential role of the inflammasome in this adjuvant’s activity. Compared to microparticle Alhydrogel this nanoalum adjuvant provided superior immunogenicity and increased protective efficacy against lethal influenza challenge. Therefore PAA:nanoalum represents a new class of alum adjuvant that preferentially enhances TH1 immunity to vaccine antigens. This adjuvant may be widely beneficial to vaccines for which TH1 immunity is important, including tuberculosis, pertussis, and malaria.

  • 23.
    Persson, Karin
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Magnér, Jörgen
    IVL Swedish Environmental Research Institute, Sweden.
    Royen, Hugo
    IVL Swedish Environmental Research Institute, Sweden.
    Filipsson, Staffan
    IVL Swedish Environmental Research Institute, Sweden.
    A Photocatalytic Membrane: for Treatment of Pharmaceuticals in Wastewater2017Report (Other academic)
    Abstract [en]

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

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

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

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  • 24.
    Sandin, Gustav
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, Trätek.
    Ahniyaz, Anwar
    Fornara, Andrea
    Peters, Greg
    Pilgård, Annica
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, Trätek.
    Johansson Salazar-Sandoval, Eric
    Svanström, Magdalena
    Xu, Yingqian
    Environmental Evaluation of a Clear Coating for Exterior Wood Products: Toxicological Testing of Nanoparticles and Life Cycle Assessment2012In: 8th International Woodcoatings Congress: Science and Technology for Sustainable Design, Paint Research Association , 2012, , p. 13Conference paper (Other academic)
  • 25.
    Skovgaard, M
    et al.
    AAK Sweden AB, Sweden.
    Gudik-Sørensen, M.
    DTU Technical University of Denmark, Denmark.
    Almdal, K.
    DTU Technical University of Denmark, Denmark.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Nanoporous zirconia microspheres prepared by salt-assisted spray drying2020In: SN Applied Sciences, ISSN 2523-3963, E-ISSN 2523-3971, Vol. 2, no 5Article in journal (Refereed)
    Abstract [en]

    Nanoporous zirconia with high surface area and crystallinity has a wide range of industrial applications, such as in inorganic exchangers for ion exchange columns, catalyst substrates, and packing material for HPLC. Spherical particles of crystalline nanoporous zirconia are highly desired in various industries due to easy handling of the materials in a fluidized bed. Here, spray drying was adopted to produce spherical nanoporous zirconia powders in both laboratory scale and pilot plant scale. Effect of salts on spray-dried ZrO2 powders and their crystallization behavior was studied. It was found that addition of salts to the zirconia precursors has a huge effect on the crystallization of nanoporous zirconia powders. These results have a great impact on the development of microspheres of nanocrystalline ZrO2 and potentially open up a new opportunity to the low-cost production of porous ceramic microspheres with the salt templating method, in general.

  • 26. Skovgaard, Mette
    et al.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Sørensen, Bent F
    Almdal, Kristoffer
    van Lelieveld, Alexander
    Effect of microscale shear stresses on the martensitic phase transformation of nanocrystalline tetragonal zirconia powders2010In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 30, no 13, p. 2749-2755Article in journal (Refereed)
    Abstract [en]

    For the first time, the effect of microscale shear stress induced by both mechanical compression and ball-milling on the phase stability of nanocrystalline tetragonal zirconia (t-ZrO2) powders was studied in water free, inert atmosphere. It was found that nanocrystalline t-ZrO2 powders are extremely sensitive to both macroscopic uniaxial compressive strain and ball-milling induced shear stress and easily transform martensitically into the monoclinic phase. A linear relationship between applied compressive stress and the degree of tetragonal to monoclinic (t→m) phase transformation was observed. Ball-milling induced microscale stress has a similar effect on the t→m phase transformation. Furthermore, it was found that even very mild milling condition, such as 120 rpm, 1 h (0.5mm balls) was enough to induce phase transformation. Surfactant assisted ball-milling was found to be very effective in de-agglomeration of our nanocrystalline porous ZrO2 particles into discrete nanocrystals. However, the t→m phase transformation could not be avoided totally even at very mild milling condition. This suggests that the metastable t-ZrO2 is extreme sensitive to microscale shear stress induced by both mechanical compression and ball-milling. The findings presented in this work are very important in further understanding the stress-induced phase transformation of nanocrystalline t-ZrO2 powders in a water free atmosphere and their further stabilization in industrially relevant solvents.

  • 27.
    Sommertune, Jens
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Sugunan, Abhilash
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Stjernberg Bejhed, Rebecca
    Uppsala University, Sweden.
    Sarwe, Anna
    RISE, Swedish ICT, Acreo.
    Johansson, Christer
    RISE, Swedish ICT, Acreo.
    Balceris, Cristoph
    Technische Universität Braunschweig, Germany.
    Ludwig, Frank
    Technische Universität Braunschweig, Germany.
    Posth, Oliver
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Fornara, Andrea
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Polymer/iron oxide nanoparticle composites—A straight forward and scalable synthesis approach2015In: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 16, no 8, p. 19752-19768Article in journal (Refereed)
    Abstract [en]

    Magnetic nanoparticle systems can be divided into single-core nanoparticles (with only one magnetic core per particle) and magnetic multi-core nanoparticles (with several magnetic cores per particle). Here, we report multi-core nanoparticle synthesis based on a controlled precipitation process within a well-defined oil in water emulsion to trap the superparamagnetic iron oxide nanoparticles (SPION) in a range of polymer matrices of choice, such as poly(styrene), poly(lactid acid), poly(methyl methacrylate), and poly(caprolactone). Multi-core particles were obtained within the Z-average size range of 130 to 340 nm. With the aim to combine the fast room temperature magnetic relaxation of small individual cores with high magnetization of the ensemble of SPIONs, we used small (<10 nm) core nanoparticles. The performed synthesis is highly flexible with respect to the choice of polymer and SPION loading and gives rise to multi-core particles with interesting magnetic properties and magnetic resonance imaging (MRI) contrast efficacy.

  • 28.
    Spezzati, Guilia
    et al.
    Eindhoven University of Technology, The Netherlands.
    Fant, Kristina
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Lundin Johnson, Maria
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Hensen, Emiel J. M.
    Eindhoven University of Technology, The Netherlands.
    Langermans, Harm
    DSM ChemTech Center, The Netherlands.
    Hofmann, Jan P.
    Eindhoven University of Technology, The Netherlands.
    Synthesis, Physicochemical Characterization, and Cytotoxicity Assessment of CeO2 Nanoparticles with Different Morphologies2017In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, Vol. 2017, no 25, p. 3184-3190Article in journal (Refereed)
    Abstract [en]

    With the growing use of nanomaterials, it is essential to carefully determine whether they represent a risk for potential users. So far, validated stand-alone methods that allow a proper risk assessment are still rare. In the present study, the cytotoxicity of CeO2 nanoparticles has been assessed. For this purpose, a variety of well-defined CeO2 nanoparticles has been prepared by using either hydrothermal synthesis or flame spray pyrolysis (FSP), resulting in nanoparticles of different morphologies and sizes. The FSP technique is known to produce particles of a very small size (in the range of nanometers), which can easily become airborne. We employed a characterization procedure that makes use of physicochemical techniques, comprising N2 physisorption, XRD, TEM, as well as ζ-potential and surface-charge measurements. The cytotoxicity of the nanoparticles was evaluated in vitro on two different human lung cell lines (A549 and MRC-5). The tests showed that, despite the differences in surface properties, size, and morphologies, neither of the CeO2 samples gave rise to a cytotoxic response.

  • 29.
    Wetterskog, Erik
    et al.
    Uppsala University, Sweden.
    Agthe, Michael
    Stockholm University, Sweden.
    Mayence, Arnaud
    Stockholm University, Sweden.
    Grins, Jekabs
    Stockholm University, Sweden.
    Wang, Dong
    Northeast Dianli University, China.
    Rana, Subhasis
    Variable Energy Cyclotron Centre, India.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Salazar-Alvarez, German
    Stockholm University, Sweden.
    Bergström, Lennart
    Stockholm University, Sweden.
    Precise control over shape and size of iron oxide nanocrystals suitable for assembly into ordered particle arrays2014In: Science and Technology of Advanced Materials, ISSN 1468-6996, E-ISSN 1878-5514, Vol. 15, no 5, p. 55010-Article in journal (Refereed)
    Abstract [en]

    Here we demonstrate how monodisperse iron oxide nanocubes and nanospheres with average sizes between 5 and 27 nm can be synthesized by thermal decomposition. The relative importance of the purity of the reactants, the ratio of oleic acid and sodium oleate, the maximum temperature, and the rate of temperature increase, on robust and reproducible size and shape-selective iron oxide nanoparticle synthesis are identified and discussed. The synthesis conditions that generate highly monodisperse iron oxide nanocubes suitable for producing large ordered arrays, or mesocrystals are described in detail.

  • 30.
    Zhao, Wei
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. Uppsala University, Sweden.
    Sugunan, Abhilash
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Gillgren, Thomas
    BillerudKorsnäs AB, Sweden.
    Larsson, Johan A
    BillerudKorsnäs AB,Sweden.
    Zhang, Zhi-Bin
    Uppsala University, Sweden.
    Zhang, Shi-Li
    Uppsala University, Sweden.
    Sommertune, Jens
    RISE Research Institutes of Sweden.
    Dobryden, Illia
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Surfactant-free starch-graphene composite films as simultaneous oxygen and water vapour barriers2022In: npj 2D Materials and Applications, ISSN 2397-7132, Vol. 6, no 1, article id 20Article in journal (Refereed)
    Abstract [en]

    A single coating formulation for multifunctional composites, such as a gas barrier against both oxygen and water vapour, is the holy grail for the packaging industry. Since the last decade, graphene has been touted as the ideal barrier material in composites due to its morphology and impermeability to all gases. However, this prospect is limited by either poor dispersion of graphene or excess surfactants to aid the dispersion, both leading to shortcuts that allow gas permeation through the composite. Here, we demonstrate a combined gas barrier with starch-graphene composite films made from a single formulation of surfactant-free starch nanoparticle-stabilized graphene dispersion (2.97 mg mL−1). Hence, the incorporated graphene reduces the permeability of both the oxygen and the water vapour by over 70% under all the relative humidity conditions tested. Moreover, these films are foldable and electrically conductive (9.5 S m−1). Our surfactant-free approach of incorporating graphene into an industrially important biopolymer is highly relevant to the packaging industry, thus offering cost-effective and water-based solution depositions of multifunctional composite films for wide-ranging applications, such as gas barriers in food packaging. © 2022, The Author(s).

  • 31.
    Zhao, Wei
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Sugunan, Abhilash
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Gillgren, Thomas
    BillerudKorsnäs AB, Sweden.
    Larsson, Johan
    BillerudKorsnäs AB, Sweden.
    Zhang, Zhi-Bin
    Uppsala University, Sweden.
    Zhang, Shi-Li
    Uppsala University, Sweden.
    Niklas, Nordgren
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Sommertune, Jens
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Surfactant-Free Stabilization of Aqueous Graphene Dispersions Using Starch as a Dispersing Agent2021In: ACS Omega, E-ISSN 2470-1343, Vol. 6, no 18, p. 12050-12062Article in journal (Refereed)
    Abstract [en]

    Attention to graphene dispersions in water with the aid of natural polymers is increasing with improved awareness of sustainability. However, the function of biopolymers that can act as dispersing agents in graphene dispersions is not well understood. In particular, the use of starch to disperse pristine graphene materials deserves further investigation. Here, we report the processing conditions of aqueous graphene dispersions using unmodified starch. We have found that the graphene content of the starch-graphene dispersion is dependent on the starch fraction. The starch-graphene sheets are few-layer graphene with a lateral size of 3.2 μm. Furthermore, topographical images of these starch-graphene sheets confirm the adsorption of starch nanoparticles with a height around 5 nm on the graphene surface. The adsorbed starch nanoparticles are ascribed to extend the storage time of the starch-graphene dispersion up to 1 month compared to spontaneous aggregation in a nonstabilized graphene dispersion without starch. Moreover, the ability to retain water by starch is reduced in the presence of graphene, likely due to environmental changes in the hydroxyl groups responsible for starch-water interactions. These findings demonstrate that starch can disperse graphene with a low oxygen content in water. The aqueous starch-graphene dispersion provides tremendous opportunities for environmental-friendly packaging applications. © 2021 American Chemical Society.

  • 32.
    Zhao, Wei
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation. Uppsala University, Sweden.
    Sugunan, Abhilash
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation.
    Zhang, Zhi-Bin
    Uppsala University, Sweden.
    Ahniyaz, Anwar
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Surface, Process and Formulation.
    Graphene and Flavin Mononucleotide Interaction in Aqueous Graphene Dispersions2019In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 43, p. 26282-26288Article in journal (Refereed)
    Abstract [en]

    A fundamental understanding of the interaction between graphene and a stabilizer is needed for the development of stable aqueous graphene dispersions. Here, we studied the interaction of graphene with the FMN in water. The UV-vis absorption spectra revealed blue shifts of the FMN absorption bands II (374 nm) and I (445 nm) in the presence of graphene. Furthermore, Fourier transform IR anal. showed that the graphene also upshifted the FMN vibration modes C10a=N1 and C4a=N5, which correspond to the FMN isoalloxazine binding sites N(1) and N(5), resp. In addition, thermogravimetric anal. showed that the thermal stability of graphene was enhanced by the adsorbed FMN, which supports the strong interaction. These results confirm that FMN adsorbs on the graphene surface in parallel conformation and hinders hydrogen bonding at the FMN isoalloxazine binding sites.

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