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Cellulose was treated with supercritical water at 668 K and 25 MPa for 0.04 s in this study. The cellulose/water system was transparent at room temperature for a while after supercritical water treatment before a precipitate gradually appeared over several hours. The precipitation process was monitored by synchrotron X-ray scattering. The scattering functions of fractal systems and flat-like structures were utilized to explain the experimentally observed small-angle scattering profiles. Immediately after supercritical water treatment, the cellulose appeared to dissolve with a fractal dimension D of approximately 1, indicating that the cellulose molecules were rigid, followed by aggregation into a 5-nm-thick flat-like structure. The flat-like structure was determined to be similar to the molecular sheets observed during the early stages of precipitation in the cellulose/aqueous sodium hydroxide and cellulose/aqueous lithium hydroxide/urea systems. Resultant regenerated cellulose had high crystallinity, large crystal size, and a low degree of polymerization.
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http://dx.doi.org/10.1016/j.carbpol.2021.118669 | DOI Listing |
Carbohydr Polym
November 2025
Institute of Nano and Biopolymeric Materials, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China. Electronic address:
This work reports an ethanol-mediated freeze-drying (EMFD) strategy that enables the scalable production of high-performance bacterial cellulose aerogels (BCAs), effectively addressing key limitations of conventional methods such as supercritical drying and standard freeze-drying, including fragility, low mechanical strength, and high cost. Specifically, by replacing water in bacterial cellulose hydrogels (BCHs) with ethanol-water solution (EWs) prior to freeze-drying, the process limits ice crystal formation and reduces capillary forces and adhesion, thereby preserving structural integrity and enhancing mechanical properties. The effects of EWs concentration on BCA morphology, volume shrinkage, mechanical strength, and pore structure were systematically investigated.
View Article and Find Full Text PDFJ Mater Chem B
September 2025
Jinling Clinical Medical College, Nanjing University of Chinese Medicine, 305 East Zhongshan Road, Nanjing 210002, P.R. China.
Research on liposome-composite hydrogel microspheres (LHMs) drug delivery systems, primarily composed of drugs, liposomes, and hydrogels, has garnered growing scientific interest. LHMs exhibit biosafety, modifiability, a wide range of loaded drug categories (water-soluble or fat-soluble), controlled and sustainable drug release capability, and specific cell-targeted performance, which compensate for the shortcomings of conventional drug delivery methods due to the complementary advantages of liposome and hydrogel microspheres. In this review, we systematically analyze the existing literature on LHMs and provide a comprehensive overview of their preparation methods.
View Article and Find Full Text PDFSmall
September 2025
Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, M5S 3G8, Canada.
In pursuit of lightweight, functional thermoplastic materials, novel monolithic aerogels composed entirely of poly(methyl methacrylate) (PMMA) and its stereocomplex crystals are reported. Herein, PMMA aerogels are fabricated using a one-pot thermoreversible gelation procedure, coupled with supercritical CO (scCO) drying. These aerogels exhibit either mixed macro- and mesoporous, or exclusively mesoporous character, with low densities (0.
View Article and Find Full Text PDFSci Rep
August 2025
Laboratory of Research Environmental Chemistry and clean processes, Faculty of Sciences of Monastir, University of Monastir, Monastir, 5019, Tunisia.
The present study focuses on the functionalization of cellulose-based textiles with residual rosemary wax, a by-product of supercritical CO₂ extraction of essential oil. The main objectives of this study were to identify the chemical composition of rosemary wax using FTIR, GC-MS, and HPLC techniques, to optimize its application onto cellulose fabrics, and to evaluate the properties of the treated textiles fabrics. In order to verify the efficacy of the treatment, a series of tests were carried out.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2025
Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013, China.
Supercritical carbon dioxide (scCO) has emerged as a promising agent in enhanced oil recovery (EOR) due to its ability to reduce interfacial tension and enhance oil mobility in reservoirs. Water is ubiquitous in oil reservoirs, yet the underlying mechanisms governing scCO transport in the presence of water within nanoscale channels remain inadequately understood. Using molecular dynamics simulations combined with analytical models, this study explores the two-phase flow behavior of scCO and water in confined nanochannels, emphasizing the effects of water saturation () and channel wettability.
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