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61.
《国际聚合物材料杂志》2012,61(10):502-509
The authors report preparation of chitosan by deacetylation of chitin extracted from shrimp shells. The quality of chitosan depended on the chemical extraction process, the concentration of chemicals used, soaking time, sequence of deproteination, decalcification, and deacetylation. Hydrogels composed of hydroxyethylmethacrylate and chitosan were subsequently prepared and their swelling and ibuprofen delivery kinetics at various chitosan concentrations were studied. The swelling properties of the network varied with the chitosan concentration. Furthermore, the swelling process followed second-order kinetics, while ibuprofen diffusion into the hydrogel showed Fickian behavior. 相似文献
62.
《国际聚合物材料杂志》2012,61(16):838-847
A fluorescent textile sensor and its capacities to detect pH changes in aqueous solutions have been reported. A new hydrogel-cotton fabric was obtained via surface initiated photopolymerization of 2-aminoethylmethacrylate hydrochloride, with N,N′-methylene-bis-acrylamide as a crosslinker, and fluorophore and modified eosin Y and N-methyldiethanolamine as photoinitiators. The synthesis of the modified eosin Y and a new 1,8-naphtalimide used as signal units in the hydrogel composite have been described. It has been found that the concentration of the photoinitiator affects the functional properties of the composite. pH variations influence the gel structure and this is transduced into fluorescence and color changes of the material. 相似文献
63.
《国际聚合物材料杂志》2012,61(17):919-926
In this research, tissue engineered hydrogels consist of chondroitin sulfate and hydroxyapatite capable of light curing and cell encapsulation were prepared. Chemical and physical characteristics were analyzed by FTIR spectroscopy, compressive strength and water uptake measurements. Observations with fluorescence microscopy as well as MTT viability assay revealed no toxicity for encapsulated cells. Moreover, alkaline phosphatase activity, calcium deposition, and gene expression analysis were determined to prove the osteogenic potential of the prepared hydrogel. In conclusion, this in situ forming hydrogel can be utilized as filler for bone deficiencies as well as carrier for cell encapsulation and osteogenic differentiation. 相似文献
64.
《国际聚合物材料杂志》2012,61(18):1108-1117
AbstractIn this study, capillary alginate gel (Capgel?), a collagen and alginate based self-assembling biomaterial, was used as a cellular scaffold for the treatment of ischemic, full-thickness dermal wounds in mice. Capgel? was synthesized using copper sulfate to form the initial sol before rinsing and stabilizing the patent capillary structures with carbodiimide chemistry. This crosslinked hydrogel was then injected into ischemic, full-thickness dermal wounds and analyzed via histology after 7 and 10 days to assess wound contracture, granulation bed tissue and vascular structures. Capgel? showed good resorbability and was well-invested with infiltrating host cells and vascular structures during and after resorption. 相似文献
65.
Tangxin Xiao Lixiang Xu Weiwei Zhong Ling Zhou Xiao-Qiang Sun Xiao-Yu Hu Leyong Wang 《Israel journal of chemistry》2018,58(11):1219-1229
Pillar[n]arenes are new generation of supramolecular macrocyclic host, which exhibit excellent host−guest recognition properties. In the last decade, functional materials constructed from pillar[n]arenes have been attracted more and more attention and displayed outstanding characteristics, such as stimuli-responsiveness, self-healing and adaptability. In this mini-review, we provide a survey of the pillar[n]arene-based literatures covering light-harvesting systems, functional hydrogels, and solid materials. It is anticipated that more and more pillar[n]arenes-based advanced materials with multi-functional properties will appear in the near future. 相似文献
66.
Character projection is a key technology to enhance throughput of E-beam lithography, in which characters need to be selected and placed on the stencil. This paper solves the problem of planning for row-structure stencil with overlapped characters and also considers multi-column cell system for further throughput improvement. We first propose an approach that is designed for characters with “regular” left and right blank spaces, which is an integrated framework to solve the subproblems of character selection, row distribution, single-row ordering and post-refinement efficiently. We then present another approach that can optimize stencil planning with general characters. Experiments show that both approaches remarkably outperform the existing methods on different sets of benchmarks. We can achieve significant throughput improvement and remarkable speed-up comparing with previous works. 相似文献
67.
Hydrogels, three‐dimensional hydrophilic polymer network structures, can absorb many times their dry weight in water. PolyHIPEs are highly porous polymers synthesized within high internal phase emulsions (HIPEs). Here, the water uptakes in novel hydrogel polyHIPE copolymers of hydroxyethyl methacrylate (HEMA, a non‐ionic monomer) and methacrylic acid (MAA, an ionic monomer) were investigated. The PHEMA‐based polyHIPE had a density of 0.14 g cm?3, void diameters of 50–100 µm and a void‐dominated Fickian water uptake of around 10.4 g g?1. The polyHIPE density increased, and the porous structure became less polyHIPE‐like, with increasing MAA content, reflecting a reduction in the stability of the HIPE. The water uptake increased with increasing pH for all the copolymers and the water absorption mechanism changed from Fickian at pH 2 to anomalous, dominantly case II, at pH 10. The maximum uptake of 18.2 g g?1 at pH 10, for a HEMA to MAA mass ratio of 1/1, was ascribed to hydrogel‐swelling‐driven void expansion. The hydrogel's absorptive and responsive properties were amplified by the polyHIPE's porous structure. These results demonstrate that the compositions of hydrogel polyHIPE copolymers can be designed to enhance their water uptake. © 2015 Society of Chemical Industry 相似文献
68.
采用水溶液聚合法,通过丙烯酰胺与白炭黑原位复合,制备出复合聚丙烯酰胺凝胶.采用高级流变仪和红外吸收光谱证实了白炭黑与聚丙烯酰胺形成的次级网络的存在,通过对比不同白炭黑填充量和不同吸水倍数对聚丙烯酰胺水凝胶模量、损耗角正切、零切黏度和流动指数的影响,发现白炭黑的加入对聚丙烯酰胺凝胶力学性能的贡献,随着白炭黑用量在0%~3... 相似文献
69.
通过将壳聚糖季铵盐化改性并交联制备了一种新型阳离子化壳聚糖水凝胶,研究了凝胶的溶胀性能和电刺激响应行为。结果表明,该凝胶在NaCl溶液中其平衡溶胀率随NaCl离子强度的增大而减小。在NaCl溶液中于非接触直流电场作用下,该凝胶向电场正极弯曲,弯曲速度和应变随外加电压的增大而增大,并随NaCl离子强度的增大到0.15处出... 相似文献
70.