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- Aguilar-Sánchez, Andrea, 1987-, et al.
(författare)
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Nano-cellulose coatings for antifouling and mechanically enhanced polyethersulfone (PES) membranes
- 2019
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Ingår i: Nordic Polymer Days 2019. ; , s. 92-92
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Konferensbidrag (refereegranskat)abstract
- Membrane technology is commonly used for filtration processes of industrial wastewater. Using membranes for water filtration is a safe and energy efficient solution. One of the main problems that arises during the usage of membranes is the fouling effects. Fouling increases the membrane separation resistance, reduces productivity due to a flux decline and affect membrane selectivity. These effects can be avoid by modifying the surface of the membranes using bio-based materials such as nano-cellulose. Nano-cellulose is a great example of a material obtained from renewable resources, which provides high reinforcement and antifouling properties to membranes.The aim of this work was the development of coatings with cellulose nano-crystals (CNC) and Tempooxidized cellulose nano-fribrils (T-CNF) using polyvinyl-alcohol (PVOH), as binding phase to enhance mechanical and antifouling properties over pure commercial PES membranes. The coatings were chemically crosslinked to increase mechanical properties and to improve stability of the coating and avoid swelling. It is expected that by avoiding swelling, permeability remains stable through time. All coating formulations remained stable after 10 hours of crossflow filtration. Mechanical properties of the coated membranes were improved in both dry and wet conditions, showing higher values of tensile strenght and E modulus compared to the uncoated ones. In addition, coated membranes showed high hydrophilicity and low adherence of bovine serum albumin (BSA).The coatings developed showed stability over PES membranes and provide them with a nanostructured surface which showed an extended durability in use. The modified surface membranes presented good mechanical properties in dry and wet conditions, high flux, high hydrophilicity, resistance to BSA fouling and to different pH environments. Moreover, these modified membranes showed promising results for fast upscaling at industrial level due to the simplicity of the coating process and the availability of the materials in the market.
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| 2. |
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| 3. |
- Aguilar Sánchez, Andrea, 1987-
(författare)
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Nanopolysaccharide coatings for functional surfaces in water-treatment materials : From mechanisms to process scalability
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, materials from renewable resources were used to develop functionalized surfaces for water treatment. The work is thus inspired by, and contributes to, the United Nations sustainable goals of: (i) clean water and sanitation, (ii) climate action, (iii) responsible consumption and production, (iv) life below water, and (v) partnerships for the goals.Nanopolysaccharides, most specifically nanocellulose and nanochitin, are great candidates for functional and renewable materials for multiple applications, including the treatment of water and wastewater. This thesis focused on the formulation of different types of nanopolysaccharide-based coatings to enhance the performance of commercially available membranes and cellulose fabrics. We developed a simple waterborne layer-by-layer cellulose nanocrystals (CNC) and TEMPO-oxidized cellulose nanofibrils (T-CNF) coating for commercially available membranes. By changing the surface and pore structure of the membrane, the coating tuned which substrates could pass through the membrane, improved antifouling performanced, and when derived from T-CNF, it was harmful to bacterial colonization. Considering the observed T-CNF’s effect on bacteria, we developed a chemically crosslinked T-CNF/Poly(vinyl) alcohol (PVA) coating with outstanding antibiofouling performance, ion adsorption/rejection combined with size exclusion, and with dimensional and pH stability. Furthermore, we used a surface-impregnation approach based on bio-based nanotechnology which resulted in highly efficient, with improved mechanical properties, and fully bio-based high-flux water filtration membranes using commercially available nonwoven fabrics. Membranes with coatings prepared from CNC, chitin nanocrystals (ChNC) and T-CNF separated particles in the size range of bacteria and viruses, and those prepared from also T-CNF showed high microplastic filtration efficiency. Moreover, membrane coating based on ChNC and T-CNF had outstanding antibacterial properties.Overall, we demonstrated that nanopolysaccharide coatings on membranes could provide a significant reduction in organic fouling and biofilm formation while enabling the adsorption of ions and separation of microplastics. In the case of biofilm formation, the functional group and surface charge of the different nanopolysaccharides determined the effect over bacteria, indicating that surfaces could be tailored against microbes. In addition, we directly compared the effect of the different nanopolysaccharides of interest (CNC, T-CNF, ligno-celullose nanocrystals (L-CNC), and ChNC) on bacterial viability and biofilm formation, and found a great difference between the different types of nanocellulose and a different mechanism for nanochitin. Thorough, none of the nanopolysaccharides displayed cytotoxic effects while in indirect contact with the bacterial cells. Nevertheless, T-CNF, ChNC and L-CNC showed a cytostatic effect on bacterial proliferation. Furthermore, the nanomechanical properties of the bacterial cells and interacting forces between the nanopolysaccharides and Escherichia coli (E. coli) were affected when in direct contact with the nanopolysaccharide surfaces.Lastly, we upscaled one of our coating processes, demonstrating that the method could be easily implemented at an industrial level. The impact of this thesis relies on the effectiveness of the coatings, the different types of functionalities observed, the demonstrated fast implementation at an industrial scale, and the potential to extrapolate this technology to other applications.
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| 4. |
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| 5. |
- Magaña, Ilse, et al.
(författare)
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Bioelastomers : current state of development
- 2022
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 10:10, s. 5019-5043
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Forskningsöversikt (refereegranskat)abstract
- Considering the current trend of finding sustainable alternatives to the existing fossil-based plastics, in this review we describe what makes a bioelastomer “bio” and what this implies in terms of materials design. We analyze the current state of development of bioelastomers, including the most important types, their current and upcoming use, and their synthetic pathways. Moreover, we provide a general landscape of the hybridization or composite preparation of elastomers to acquire specific functionalities and their implementation in advanced applications, focusing mainly on electronics and biomedicine. Furthermore, we show how through the use of bioelastomers, one can, besides helping the environment, achieve materials with exceptional performances (e.g., very high mechanical properties and/or self-healing properties), which can be processed via novel techniques such as 3/4D-(bio)printing.
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| 6. |
- Pöhler, Tiina, et al.
(författare)
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Pilot-scale modification of polyethersulfone membrane with a size and charge selective nanocellulose layer
- 2022
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Ingår i: Separation and Purification Technology. - : Elsevier BV. - 1383-5866 .- 1873-3794. ; 285
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Tidskriftsartikel (refereegranskat)abstract
- The utilisation of plant-derived nanoscale cellulosic materials (cellulose nanofibrils, CNF) in tailoring water purification membranes is constantly gaining interest in the context of green-functionalised membrane solutions. However, most of the existing approaches based on renewable and biobased materials suffer from the lack of efficient and scalable processing strategies. Here, we introduce a roll-to-roll membrane modification approach based on thin submicron nanocellulose coatings (400–800 nm) to manufacture anti-biofouling membranes with size and charge dependent selectivity using unit operations compatible with existing industrial lines. We turned a commercial polymeric polyethersulfone (PES) microfiltration membrane into highly hydrophilic and tight membrane structure by applying thin and water-durable cellulose nanofibril layers using cast or spray coating methods. Nanocellulose coated membranes exhibited water permeance values of 80 – 100 LMH/MPa with the highest rejection levels of > 90% for Cytochrome C. Furthermore, the nanocellulose layers were able to withstand relatively high filtration pressure levels of 1 MPa, indicating that the selected procedures to improve mechanical integrity i.e. polyethylene imine-based anchoring and acid induced CNF cross-linking were successful. The coated membranes with the thinnest nanocellulose layer exhibited a molecular weight cut-off (MWCO) of 2 kDa for negatively charged polystyrene sulfonate and 14 kDa for neutral dextrane indicating charge selective behaviour. It can be concluded that our nanocellulose coated PES membranes represent nanofiltration membranes and lower boundary of ultrafiltration membranes with clear anti-biofouling performance directly evidenced via systematic bovine serum albumin (BSA) adsorption investigations. Our approach paves the way towards tunable and sustainable water treatment technologies simultaneously opening space for novel biobased solutions in membrane sector.
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| 7. |
- Valencia, Luis, 1990-, et al.
(författare)
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Bio-based Micro-/Meso-/Macroporous Hybrid Foams with Ultrahigh Zeolite Loadings for Selective Capture of Carbon Dioxide
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:43, s. 40424-40431
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Tidskriftsartikel (refereegranskat)abstract
- Microporous (<2 nm) crystalline aluminosilicates in the form of zeolites offer a great potential as efficient adsorbents for atmospheric CO2 in the eminent battle against global warming and climate change. The processability of conventional zeolite powders is, however, poor, which limits their implementation in many applications, such as in gas filtration industrial systems. In this work, we overcome this issue through the preparation of hybrid foams using mesoporous/macroporous supporting materials based on the strong network properties of gelatin/nanocellulose, which can support ultrahigh loadings of silicalite-1, used as a model sorbent nanomaterial. We achieved up to 90 wt % of zeolite content and a microporous/mesoporous/macroporous hybrid material. The application of hybrid foams for selective CO2 sorption exhibits a linear relationship between the zeolite content and CO2 adsorption capacity and high selectivity over N2, where the gelatin/nanocellulose foam efficiently supports the zeolite crystals without apparently blocking their pores.
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