Organic onium hydroxide aqueous solutions (OHAS) are demonstrated to be potential solvents for the dissolution of lignin and its epoxidation. A series of OHAS has been assessed in terms of the solubility of soda lignin (SL) and Klason lignin (KL), which are moderately and rarely soluble in NaOH aq. soln., respectively. Tetrabutylphosphonium hydroxide ([P]OH) aqueous solution was found to exhibit a highest solubility, specifically 40 wt% of SL and 3.0 wt% of KL. The superior solubility of OHAS is comprehended to be due to weak interactions between OH anions and phosphonium cations, and hence OH anions interact effectively with lignin. Epoxidation of SL was achieved by simply adding epichlorohydrin to [P]OH aq. dissolving SL. Films of epoxidized SL were prepared by thermal curing with the aid of a crosslinking agent, and the films were found to possess high thermal stability of >250 °C and excellent ductility. The thermal and mechanical properties were controllable by the concentration of [P]Cl as an additive.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.03.152 | DOI Listing |
Sci Rep
May 2024
School of Chemistry and Life Sciences, Hanoi University of Science and Technology, No. 1 Dai Co Viet Street, 10000, Hanoi, Vietnam.
Sustainable cellulose-based hydrogels are used in medicine and environmental science. Hydrogels' porosity makes them excellent adsorbents and stable substrates for immobilizing photocatalysts to remove organic dyes. Despite their potential, the implementation of hydrogels for this purpose is still limited due to their high synthesis temperature and low cellulose content.
View Article and Find Full Text PDFGels
March 2024
Department of Biological Engineering, Konkuk University, Seoul 05029, Republic of Korea.
In this study, cellulose/FeO hydrogel microbeads were prepared through the sol-gel transition of a solvent-in-oil emulsion using various cellulose-dissolving solvents and soybean oil without surfactants. Particularly, 40% tetrabutylammonium hydroxide (TBAH) and 40% tetrabutylphosphonium hydroxide (TBPH) dissolved cellulose at room temperature and effectively dispersed FeO, forming cellulose/FeO microbeads with an average diameter of ~15 µm. Additionally, these solvents co-dissolved cellulose and silk, allowing for the manufacture of cellulose/silk/FeO hydrogel microbeads with altered surface characteristics.
View Article and Find Full Text PDFBiosensors (Basel)
March 2023
Instituto de Engenharia de Sistemas e Computadores-Microsistemas e Nanotecnologias (INESC MN), 1000-029 Lisbon, Portugal.
Prostate cancer (PCa) is one of the cancer types that most affects males worldwide and is among the highest contributors to cancer mortality rates. Therefore, there is an urgent need to find strategies to improve the diagnosis of PCa. Microtechnologies have been gaining ground in biomedical devices, with microfluidics and lab-on-chip systems potentially revolutionizing medical diagnostics.
View Article and Find Full Text PDFiScience
January 2023
Guangxi Key Laboratory of Processing for Nonferrous Metallic and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Nanocrystalline cellulose (NCC) preparation in an integrated fractionation manner is expected to solve the problems of low yield and environmental impact in the traditional process. An integrated fractionation strategy for NCC production from wood was developed through catalytic biomass fractionation, the partial dissolution of cellulose-rich materials (CRMs) in aqueous tetrabutylphosphonium hydroxide, and short-term ultrasonication. The presented process could tolerate a high CRM lignin content of 21.
View Article and Find Full Text PDFSci Rep
August 2022
Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto, 606-8522, Japan.
Six PF-based ionic liquids (ILs) were investigated to evaluate their potential as chemicals for enhancing fire and termite resistance of wood. The ILs used in this study included 1-methyl-1-propylpyrrolidinium hexafluorophosphate ([MPPL]PF), 1-methyl-1-propylpiperidinium hexafluorophosphate ([MPPR]PF), 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM]PF), tetrabutylphosphonium hexafluorophosphate ([TBP]PF), trihexyltetradecylphosphonium hexafluorophosphate ([THP]PF), and 1-butylpyridinium hexafluorophosphate ([BPYR]PF). All of the IL-treated wood samples did not undergo any morphological changes, and exhibited enhanced fire- and termite resistance compared with untreated wood.
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