| 1. |
- Capezza, Antonio Jose, et al.
(author)
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High Capacity Functionalized Protein Superabsorbents from an Agricultural Co‐Product: A Cradle‐to‐Cradle Approach
- 2020
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In: Advanced Sustainable Systems. - : Wiley. - 2366-7486.
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Journal article (peer-reviewed)abstract
- Synthesis of superabsorbent particles from nontoxic wheat gluten (WG) protein, as an industrial co‐product, is presented. A natural molecular cross‐linker named genipin (a hydrogenated glycoside) is used together with a dianhydride (ethylenediaminetetraacetic EDTAD), to enable the preparation of a material with a network structure capable of swelling up to ≈4000% in water and ≈600% in saline solution. This represents an increase in swelling by over 10 times compared to the already highly absorbing gluten reference material. The carboxylation (using EDTAD) and the cross‐linking of the protein result in a hydrogel with liquid retention capacity as high as 80% of the absorbed water remaining in the WG network on extensive centrifugation, which is higher than that of commercial fossil‐based superabsorbents. The results also show that more polar forms of the reacted genipin are more effectively grafted onto the protein, contributing to the swelling and liquid retention. Microscopy of the materials reveals extensive nanoporosity (300 nm), contributing to rapid capillarity‐driven absorption. The use of proteins from agricultural industries for the fabrication of sustainable protein superabsorbents is herein described as an emerging avenue for the development of the next generation daily‐care products with a minimal environmental impact.
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| 2. |
- Engel, Emile, et al.
(author)
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Composite Hydrogel Spheroids Based on Cellulose Nanofibrils and Nanofibrous Chiral Coordination Polymer by Green Synthesis
- 2020
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In: Advanced Sustainable Systems. - : Wiley-VCH Verlag. - 2366-7486.
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Journal article (peer-reviewed)abstract
- Cellulose-based hydrogels are promising sustainable materials for a variety of applications, including tissue engineering, water treatment, and drug delivery. However, the tailoring of diverse properties by efficient green chemistry methods is an ongoing challenge. Here, composite hydrogels of consistent spheroidal structure, incorporating TEMPO-oxidized cellulose nanofibrils and nanofibrous chiral Cu(II) aspartate coordination polymer, are presented. The hydrogels are prepared by a single-step procedure in aqueous media at ambient temperature and pressure, adhering to the principles of green chemistry. With a view to adapting this method for a variety of alternative coordination polymers (to tailor functional properties), the following critical factors for formation of robust composite hydrogel spheroids are identified: rheological properties of the primary matrix used for spheroidal hydrogel formation and coordination polymer self-assembly rate.
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| 3. |
- Han, Shaobo, et al.
(author)
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Cellulose-Conducting Polymer Aerogels for Efficient Solar Steam Generation
- 2020
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In: Advanced Sustainable Systems. - : Wiley-VCH Verlag. - 2366-7486. ; 4:7, s. 2000004-
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Journal article (peer-reviewed)abstract
- Seawater desalination and wastewater purification technologies are the main strategies against the global fresh water shortage. Among these technologies, solar-driven evaporation is effective in extracting fresh water by efficiently exploiting solar energy. However, building a sustainable and low-cost solar steam generator with high conversion efficiency is still a challenge. Here, pure organic aerogels comprising a cellulose scaffold decorated with an organic conducting polymer absorbing in the infrared are employed to establish a high performance solar steam generator. The low density of the aerogel ensures minimal material requirements, while simultaneously satisfying efficient water transport. To localize the absorbed solar energy and make the system floatable, a porous floating and thermal-insulating foam is placed between the water and the aerogel. Thanks to the high absorbance of the aerogel and the thermal-localization performance of the foam, the system exhibits a high water evaporation rate of 1.61 kg m−2 h−1 at 1 kW m−2 under 1 sun irradiation, which is higher than most reported solar steam generation devices.
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| 4. |
- Méhes, Gábor, et al.
(author)
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Solar Heat-Enhanced Energy Conversion in Devices Based on Photosynthetic Membranes and PEDOT:PSS-Nanocellulose Electrodes
- 2020
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In: Advanced Sustainable Systems. - : Wiley-VCH Verlag. - 2366-7486. ; 4:1
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Journal article (peer-reviewed)abstract
- Energy harvesting from photosynthetic membranes, proteins, or bacteria through bio-photovoltaic or bio-electrochemical approaches has been proposed as a new route to clean energy. A major shortcoming of these and solar cell technologies is the underutilization of solar irradiation wavelengths in the IR region, especially those in the far IR region. Here, a biohybrid energy-harvesting device is demonstrated that exploits IR radiation, via convection and thermoelectric effects, to improve the resulting energy conversion performance. A composite of nanocellulose and the conducting polymer system poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is used as the anode in biohybrid cells that includes thylakoid membranes (TMs) and redox mediators (RMs) in solution. By irradiating the conducting polymer electrode by an IR light-emitting diode, a sixfold enhancement in the harvested bio-photovoltaic power is achieved, without compromising stability of operation. Investigation of the output currents reveals that IR irradiation generates convective heat transfer in the electrolyte bulk, which enhances the redox reactions of RMs at the anode by suppressing diffusion limitations. In addition, a fast-transient thermoelectric component, originating from the PEDOT:PSS-nanocellulose-electrolyte interphase, further increases the bio-photocurrent. These results pave the way for the development of energy-harvesting biohybrids that make use of heat, via IR absorption, to enhance energy conversion efficiency.
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| 5. |
- Sharma, P. R., et al.
(author)
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Nanocellulose-Enabled Membranes for Water Purification : Perspectives
- 2020
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In: Advanced Sustainable Systems. - : Wiley. - 2366-7486. ; 4:5
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Journal article (peer-reviewed)abstract
- Membrane technology remains the most energy-efficient process for removing contaminants (micrometer-size particles to angstrom-size hydrated ions) from water. However, the current membrane technology, involving relatively expensive synthetic materials, is often nonsustainable for the poorest communities in the society. In this article, perspectives are provided on the emerging nanocellulose-enabled membrane technology based on nanoscale cellulose fibers that can be extracted from almost any biomass. It is conceivable that nanocellulose membranes developed from inexpensive, abundant, and sustainable resources (such as agriculture residues and underutilized biomass waste) can lower the cost of membrane separation, as these membranes offer the ability to remove a range of pollutants in one step, via size exclusion and/or adsorption. The nanocellulose-enabled membrane technology not only may be suitable for tackling global drinking water challenges, but it can also provide a new low-cost platform for various pressure-driven filtration techniques, such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. Some relevant parameters that can control the filtration performance of nanocellulose-enabled membranes are comprehensively discussed. A short review of the current state of development for nanocellulose membranes is also provided.
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