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51.
Katsuki Kusakabe Kiyotaka IchikiJun-ichiro Hayashi Hideaki MaedaShigeharu Morooka 《Journal of membrane science》1996
Silica-polyimide microcomposite membranes were prepared on γ-alumina-coated α-alumina support tubes, and their gas permeation properties were evaluated with He, N2 and CO2. Smoothing of the substrate surface and hybridization of silica and polyamic acid were both effective to form defect-free thin composite membranes. The CO2 permeance of a membrane with a silica content of 68 wt% was one order of magnitude higher than that of a polyimide membrane having the same thickness. The permselectivity of CO2 to N2 was 30 at 30°C and 13 at 100°C. Contributions of the silica and polyimide phases to permeance of the composite membrane were analyzed with a two-phase permeation model. The effective thickness of the rate-controlling polyimide phase was less than one-tenth of the total thickness of the silica-polyimide membrane. 相似文献
52.
酞菁氧钛/卟啉氧钒复合体系光导性能的协同增强效应 总被引:9,自引:0,他引:9
在酞菁氧钛(TiOPc)/卟啉氧钒(VOTPP)复合光生材料中发现了光敏性的非线性增强现象,对复合体系的电子跃迁光谱和X射线衍射图的研究结果表明,在基态下两种材料之间没有明显相互作用,光致放电研究说明,该现象来自光激发状态下复合体系中的隙间态跃迁对光导的贡献,XPS测试结果表明酞菁氧钛与卟啉氧钒分子之间存在着定向的部分电荷转移,光致激发状态下的电荷转移是协同增强效应的起因,这种协同增强效应为利用弱的电子给体与弱的受体复合体系设计新型光导材料与器件提供了新方法。 相似文献
53.
Pengchong Li Zhi Shang Kejian Cui Huan Zhang Zhi Qiao Caizhen Zhu Ning Zhao Jian Xu 《中国化学快报》2019,30(1):157-159
Polystyrene (PS) fibers with core-shell structure were prepared by coaxial electrostatic spinning using liquid epoxy or curing agent as the core and PS solution as the shell. Scratch self-healing coatings were realized by using the healant-loaded core-shell fibers in the matrix. 相似文献
54.
Sumio Sakka 《Journal of Sol-Gel Science and Technology》1994,2(1-3):451-455
The present state of our knowledge on sol-gel coating films has been reviewed. A qualitative discussion is made on the limit of the film thickness which can be achieved in the sol-gel method and the factors affecting the film thickness. Considering that properties of the film are intimately related to the microstructure, types of microstructures accomplished by the sol-gel coating are introduced with examples. 相似文献
55.
56.
《Surface and interface analysis : SIA》2003,35(4):369-374
Polyester‐based polyurethane/nanosilica composites were prepared via in situ polymerization and investigated by contact angle measurement, transmission electron microscopy (TEM), atomic force microscopy (AFM) and peel testing in an Instron testing machine. The contact angle and surface free energy results show that nanosilica tended to enrich at the interface between nanocomposite polymers and the substrates, TEM indicated that nanosilica particles were evenly dispersed in the bulk and AFM demonstrated that nanoparticles were located at both the surfaces and interfaces of nanocomposite polymers and that the roughness of both the surfaces and interfaces had a decreasing tendency as the nanosilica content increased, as did the adhesion strength between the nanocomposite polymers and substrates. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
57.
采用溶胶-凝胶法制备无孔脲醛树脂-二氧化锆复合微球,在碳酸盐缓冲溶液中,利用微球表面的酰胺键与三嗪染料-活性艳蓝X-BR分子中三嗪环上的活泼氯反应,将染料键合到微球表面,以牛血清白蛋白(BSA)为样品,考察了不同条件下,该萃取剂对BSA的萃取能力。结果表明,该萃取剂对BSA的饱和萃取量达到30.3 mg.g-1,同时萃取的蛋白易于洗脱,1.0 mol.L-1氰化钾的洗脱率达到93.5%。 相似文献
58.
肝素化壳聚糖季铵盐/壳聚糖复合膜抗凝血性能的研究 总被引:13,自引:1,他引:13
以壳聚糖季铵盐,壳聚糖为基本原材料,选用戊二醛为交剂剂及固定剂,制备一种物理机械性能较优的抗凝血材料。探讨了戊二醛及肝素钠两者用量对肝素化程度及血液生的影响。 相似文献
59.
Two simple modification methods for ordered mesoporous silicas were examined and compared. MCM-41 molecular sieve was physically coated with 4-cyano-4-biphenyl [4(4-pentenyloxy)]benzoate (CBPB) and chemically modified using trimethylethoxysilane. The structural and surface properties of the obtained materials were characterized using elemental analysis, thermogravimetry and nitrogen adsorption over a wide pressure range.It was shown that the pore size of the MCM-41 material was not decreased significantly after the coating procedure, even for high loadings of CBPB. Moreover, low pressure adsorption measurements indicated that significant fractions of the MCM-41 surface were not covered by CBPB, even for high CBPB loadings, which suggests that the attained coverage may be very nonuniform. The chemical bonding procedure led to a marked decrease in the pore size and change of surface properties.It was demonstrated that nitrogen adsorption measurements provide a means of a thorough characterization of modified MCM-41 materials, allowing to estimate the surface area, pore volume and pore size distribution. Moreover, low pressure adsorption data can be used to qualitatively or semiquantitatively assess the surface coverage of the coated/bonded organic groups, which may be used to estimate the uniformity of the coverage and therefore, the usefulness of the modification procedure. 相似文献
60.
Control of the optical properties of gel-derived oxide films containing fine metal particles is described. The duration of the aging of Si(OC2H5)4-derived sols and the amount of water for hydrolyzing Si(OC2H5)4 were found to greatly affect the size and the shape of Au particles formed in the silica matrix, and accordingly the optical absorption of the Au/SiO2 composite films. Employing dielectric media with high refractive indices like TiO2 was shown to shift the absorption peak of Au particles to longer wavelengths. Pd/TiO2 and Pt/TiO2 composite films showed absorption in the visible region. 相似文献