| 1. |
- Ahmed, Fareed, et al.
(författare)
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Manufacturing Poly(3,4-Ethylenedioxythiophene) Electrocatalytic Sheets for Large-Scale H2O2 Production
- 2022
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Ingår i: Advanced Sustainable Systems. - : John Wiley and Sons Inc. - 2366-7486. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Producing thick films of conducting polymers by a low-cost manufacturing technique would enable new applications. However, removing huge solvent volume from diluted suspension or dispersion (1–3 wt%) in which conducting polymers are typically obtained is a true manufacturing challenge. In this work, a procedure is proposed to quickly remove water from the conducting polymer poly(3,4-ethylenedioxythiophene:poly(4-styrene sulfonate) (PEDOT:PSS) suspension. The PEDOT:PSS suspension is first flocculated with 1 m H2SO4 transforming PEDOT nanoparticles (≈50–500 nm) into soft microparticles. A filtration process inspired by pulp dewatering in a paper machine on a wire mesh with apertures dimension between 60 µm and 0.5 mm leads to thick free-standing films (≈0.5 mm). Wire mesh clogging that hinders dewatering (known as dead-end filtration) is overcome by adding to the flocculated PEDOT:PSS dispersion carbon fibers that aggregate and form efficient water channels. Moreover, this enables fast formation of thick layers under simple atmospheric pressure filtration, thus making the process truly scalable. Thick freestanding PEDOT films thus obtained are used as electrocatalysts for efficient reduction of oxygen to hydrogen peroxide, a promising green chemical and fuel. The inhomogeneity of the films does not affect their electrochemical function. © 2021 The Authors.
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| 2. |
- Cebrian, Ariane V.S., et al.
(författare)
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Development of Conformable Substrates for OLEDs Using Highly Transparent Bacterial Cellulose Modified with Recycled Polystyrene
- 2022
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial cellulose (BC) is a biocompatible and nontoxic biopolymer that has been successfully used as a substrate for flexible organic light emitting diodes (OLEDs). Although BC membranes exhibit excellent mechanical properties and industrial scalability, they are semitransparent, which limits their performance. To improve the optical properties of BC membranes, methods such as the polymerization of different inorganic–organic hybrid materials and petrochemical derivative monomers have been considered; however, these methods require considerable time and effort. In this work, transparent BC membranes for conformable OLEDs substrates are fabricated by spray coating a solution of recycled petrochemical plastics, found in expanded foam package wastes, and d-limonene, which is a green solvent extracted from orange peels. This fabrication approach is highly scalable and can be considered a sustainable technique to develop high performance transparent substrates for photonic applications based on both recovered petrochemical polymers and naturally occurring biopolymers. In terms of the morphological and structural properties, the resulting transparent membranes exhibit a lower roughness than pristine BC. The resulting BC-PS composite is used as a substrate for OLED fabrication. The conformable OLEDs exhibit a current efficiency of up to 5 cd A−1 (16 000 cd m−2) and power density of ≈2.8 mW cm−2.
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| 3. |
- Lander, Sanna, 1990-, et al.
(författare)
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Sulfonated Cellulose Membranes: Physicochemical Properties and Ionic Transport versus Degree of Sulfonation
- 2022
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486. ; 6:11
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Tidskriftsartikel (refereegranskat)abstract
- The next generation of green ion selective membranes is foreseen to be based on cellulosic nanomaterials with controllable properties. The introduction of ionic groups into the cellulose structure via chemical modification is one strategy to obtain desired functionalities. In this work, bleached softwood fibers are oxidatively sulfonated and thereafter homogenized to liberate the cellulose nanofibrils (CNFs) from the fiber walls. The liberated CNFs are subsequently used to prepare and characterize novel cellulose membranes. It is found that the degree of sulfonation collectively affects several important properties of the membranes via the density of fixed charged groups on the surfaces of the CNFs, in particular the membrane morphology, water uptake and swelling, and correspondingly the ionic transport. Both ionic conductivity and cation transport increase with the increased level of sulfonation of the starting material. Thus, it is shown that the chemical modification of the CNFs can be used as a tool for precise and rational design of green ion selective membranes that can replace expensive conventional fluorinated ionomer membranes.
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| 4. |
- Ngoc Pham, Tung, et al.
(författare)
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Core–shell carbon nanofibers‐NiFe structure on 3D porous carbon foam : facilitating a promising trajectory toward decarbonizing energy production
- 2022
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Ingår i: Advanced sustainable systems. - : Wiley-VCH Verlagsgesellschaft. - 2366-7486. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a low-cost, light-weight, highly efficient, and durable electrode in which NiFe-layered double hydroxide is electrodeposited on a carbon nanofiber (CNF) core supported on a carbon foam (CF) is introduced. The resulting 3D NiFe-CNFs-CF electrode shows excellent oxygen evolution reaction and hydrogen evolution reaction performance in alkaline media. When used as an anode and a cathode in the same cell, a current density of 10 mA cm−2 is achieved, at a cell voltage of 1.65 V. Moreover, good stability over a long testing time (50 h) is demonstrated. The ternary hybrid electrode gives rise to an excellent performance-to-weight ratio owing to its very low bulk density (≈34 mg cm−3) inherited from super lightweight components composed of CF and CNFs. The developed electrode can potentially be used in large-scale alkaline water electrolysis, in facilities such as offshore hydrogen production platforms, which can complement the variable renewable energy production of wind farms through hydrogen storage and fuel cells.
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| 5. |
- Samanta, Archana, Post doc Researcher, et al.
(författare)
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Charge Regulated Diffusion of Silica Nanoparticles into Wood for Flame Retardant Transparent Wood
- 2022
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486 .- 2366-7486. ; 6:4, s. 2100354-2100354
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Tidskriftsartikel (refereegranskat)abstract
- The preparation of wood substrates modified by charged inorganic nanoparticles (NPs) diffusing into the internal cell wall structure is investigated for generating functional properties. The flammability problem of wood biocomposites is addressed. NPs applied from colloidal sols carry charge to stabilize them against aggregation. The influence of charge on particle diffusion and adsorption should play a role for their spatial distribution and localization in the wood substrate biocomposite. It is hypothesized that improved dispersion, infiltration, and stability of NPs into the wood structure can be achieved by charge control diffusion, also restricting NP agglomeration and limiting distribution to the wood cell wall. Cationic and anionic silica NPs of ≈30 nm are therefore allowed to diffuse into bleached wood. The influence of charge on distribution in wood is investigated as a function of initial sol concentration. Transparent wood is fabricated by in situ polymerization of a thiolene in the wood pore space. These biocomposites demonstrate excellent flame retardancy with selfextinguishing characteristics. The approach has potential for commercial fabrication of flame retardant transparent composites for glazing and other building applications.
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