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排序方式: 共有125条查询结果,搜索用时 8 毫秒
91.
92.
《Journal of Saudi Chemical Society》2022,26(6):101561
Biopolymers like cellulose, polysaccharides, chitosan, starch, chitin, and alginates have sparked an increasing curiosity in creating natural replacements for synthetic polymers during the last several decades. Chitin is a major part of fungi’s cell walls, the crustaceans’ exoskeletons, like lobsters, crabs, and shrimps, cephalopod beaks, the radulae of mollusks, and fish and lissamphibians scales. Since the late 1970 s, biopolymer chitosan has gathered interest in basic science and applied research due to its incredible macromolecular framework, physicochemical properties, and biological activities, which differ from those of synthetic polymers. Chitin and derivatives thereof have practical usages in chemistry, the agriculture sector, medicine, cosmetics, as well as textile and paper industries. Chitosan has also received a lot of recent interest in the fields of dentistry, ophthalmology, veterinary science, biomedicine, the drink industry, hygiene and personal care, catalysis, chromatography, sewage treatment, and biotechnology. Numerous fundamental investigations have been conducted on chitin and chitosan. This article presents a short compact summary of research over the last two decades in an attempt to highlight the works on chitin and chitosan applications. 相似文献
93.
Dr. Rafael F. A. Gomes Dr. Bruno M. F. Gonçalves Késsia H. S. Andrade Bárbara B. Sousa Prof. Nuno Maulide Prof. Gonçalo J. L. Bernardes Prof. Carlos A. M. Afonso 《Angewandte Chemie (International ed. in English)》2023,62(28):e202304449
The demand for new biomass-derived fine and commodity chemicals propels the discovery of new methodologies and synthons. Whereas furfural and 5-hydroxymethylfurfural are cornerstones of sustainable chemistry, 3-acetamido-5-acetyl furan (3A5AF), an N-rich furan obtained from chitin biomass, remains unexplored, due to the poor reactivity of the acetyl group relative to previous furanic aldehydes. Here we developed a reactive 3-acetamido-5-furfuryl aldehyde (3A5F) and demonstrated the utility of this synthon as a source of bio-derived nitrogen-rich heteroaromatics, carbocycles, and as a bioconjugation reagent. 相似文献
94.
Yuling Ma Dongyan Liu Xiaotan Zhang 《Journal of Dispersion Science and Technology》2017,38(12):1798-1803
The role of negative charges on cellulose nanowhiskers (CNWs) in the aqueous dispersion behaviors of graphene has been investigated. The sulfate groups were partially removed from the CNWs with sodium hydroxide solution. Both CNWs and desulfated cellulose nanowhiskers (D-CNWs) were applied in the aqueous dispersion process of graphene. The dispersing result was evaluated by ultraviolet-visible (UV-Vis) absorption spectra. It revealed the dispersing ability of D-CNWs became worse due to the removal of sulfate groups. It demonstrated the negative charged sulfate groups on CNWs played an important role in the graphene dispersing process. 相似文献
95.
96.
甲壳素溶致液晶的研究 总被引:5,自引:0,他引:5
报道了甲壳素有溶致液晶性.对四种不同分子量的甲壳素的研究结果表明,分子量增大,临界浓度显著降低,胆甾相平均螺距减少,但液晶有序微区平均尺寸却增加.甲壳素分子量为284×106、147×106、94×105和53×105时,在二氯乙酸中的临界浓度(W/W)分别为0005、0015、0035和0050.根据理论分析,甲壳素可视为刚性链,与多肽相似.甲壳素的指纹状织构不同于其他溶致液晶体系,在各种分子量甲壳素的两相共存浓度区内,液晶有序存在于内含指纹的不规则微区内,而不是滴状微区内. 相似文献
97.
甲壳素碱介质非均相脱乙酰动力学研究 总被引:11,自引:0,他引:11
陈炳稔 《高等学校化学学报》1992,13(7):1008-1009
近年来,从甲壳素(聚[(1,4)-2-乙酰胺基-2-脱氧-β-D-葡萄糖])制备壳聚糖的研究和生产以及对其理论和应用的探索,越来越广泛和深入。甲壳素脱乙酰基转变成壳聚糖,由于反应条件不同,所得产品不仅结构性能不同,而且影响其深加工产品的质量.因此,对甲壳素脱乙酰基反应的研究引起国内外学者的重视.Sannan等曾报道甲壳素在碱介质中均相脱乙酰动力学的研究,但对非均相条件下脱乙酰动力学的研究,国内外至今尚未见报道.目 相似文献
98.
Aiming at the combination of the biological properties of chitin and the mechanical and thermal characteristics of polyurethane, the two polymers were combined in two macromolecular configurations. In the first, the polymers were mixed forming blends and in the second tridimensional networks were built. The potential application of the two systems as biomedical materials was studied, showing that both blends and networks presented high stability with low mass loss in media simulating living tissue. No toxic products were released and the adhesion to Vero cells was low. These preliminary results in vitro indicated that the materials are potentially biocompatible, with potential bio medical applications. 相似文献
99.
100.
Self-assembled natural biomaterials offer a variety of ready-made nanostructures available for basic science research and technological applications. Most natural structural materials are made of self-assembled nanofibers with diameters in the nanometer range. Among these materials, chitin is the second most abundant polysaccharide after cellulose and is part of the exoskeleton or arthropods and mollusk shells. Chitin has several desirable properties as a biomaterial including mechanical strength, chemical and thermal stability, and biocompatibility. However, chitin insolubility in most organic solvents has somewhat limited its use. In this research highlight, we describe recent developments in producing biogenic chitin nanofibers using self-assembly from a solution of squid pen β-chitin in hexafluoroisopropanol. With this solution based assembly, we have demonstrated chitin-silk composite self-assembly, chitin nanofiber fabrication across length-scales, and manufacturing of chitin nanofiber substrates for tissue engineering. 相似文献