无机-有机杂化复合反渗透膜的研究进展

无机-有机杂化复合反渗透膜结合了有机膜和无机材料的优良性能,已成为复合反渗透膜领域研究的热点之一.主要介绍了无机-有机杂化复合反渗透膜的制备、分类、结构和性能,并针对杂化复合反渗透膜研究中现存的问题和今后的研究方向,提出了一些建议.     

溶胶-凝胶法制备PDMS/SiO2杂化材料

采用sol-gel工艺,以正硅酸乙酯(TEOS)为无机组分前驱物,以含端羟基的聚二甲基硅氧烷(PDMS)为有机组分,分别采用盐酸、草酸、氨水、三乙醇胺为催化剂,合成了PDMS/SiO2杂化材料,讨论了催化剂、共溶剂对杂化材料的影响,考察了杂化材料收缩率及透光率.结果表明:采用草酸作催化剂合成了块状、透明的杂化材料,PDMS/SiO2杂化材料的收缩率随共溶剂用量的增加和PDMS用量的减小而增加,采用羟基含量为4%的PDMS合成的杂化材料的透明性较好.     

溶胶—凝胶法制备Al2O3—SiO2陶瓷薄膜的研究

研究了溶胶－凝胶（Ｓｏｌ－Ｇｅｌ）法制备Ａｌ２Ｏ３－ＳｉＯ２体系多孔的陶瓷膜过程中的溶胶、凝胶反应，通过冷冻复型法观察到溶胶颗粒的微观形貌，认为组分之间的去极化作用是导致溶胶颗粒团聚的原因，利用ＦＴＩＲ地复合交的热处理过程反应情况进行观察，结果表明，组分各自的相变互不影响，也不发生反应，由此可制得保持各组分特性的Ａｌ２Ｏ３－ＳｉＯ２复合陶瓷薄复合薄膜的ＴＥＭ形貌表明，组分在溶胶状太的去极化作用地致     

纳米SiO_2有机杂化膜制备研究

采用共混法和溶胶-凝胶法制备了纳米SiO_2有机杂化膜,考察了制备方法和SiO_2的性质对杂化膜结构和性能的影响.结果表明:采用溶胶-凝胶技术制备的杂化膜同共混法得到的杂化膜及未杂化膜相比,机械性能明显提高,膜微观结构改善,并表现出良好的气体分离性能.此外,杂化膜中无机相的负载量也是一个影响杂化膜结构和性能的重要因素,当正硅酸乙酯的添加量为30%(wt)时,杂化膜的综合性能较为理想.     

Preparation of inorganic-organic hybrid films containing particles using electrophoretic deposition method

The composite films of methylsiloxane inorganic-organic hybrid and MoS₂ particles have successfully been fabricated by electrophoretic deposition of MoS₂ particles in a mixed solution of methyl ethyl ketone (MEK) and inorganic-organic hybrid sol. The addition of 20 vol% hybrid sol into a MEK suspension increased the amount of MoS₂ deposition twice as much as that of MoS₂ deposition in MEK alone. The fraction of particles deposited on a substrate in MEK-20 vol% sol was estimated to be much larger than that in MEK. The hydrolyzed methyltriethoxysilane in a hybrid sol modified MoS₂ particles, resulting in lower negative zeta potential, which reduces the repulsion force among particles and makes the incorporation of particles into a deposition film easier. The surface modification also enables the incorporation of particles into a deposit by the interaction of surface modifiers. These factors enhance the incorporation of MoS₂ particles in electrophoretic deposition in MEK-sol.     

Preparation of silica monolith via sol-gel route

The present investigation deals with the synthesis of monolithic NiCl₂-silica gels obtained by hydrolysis and polycondensation of tetraethoxy silanes. This sol to gel formation can mainly be controlled by adjusting some variables e.g. acid content of the solution, ageing and leaching times. A minimum acid content was found necessary to prepare uncracked gel while ageing and leaching times were found to be not that sensitive for the formation of uncracked gels.     

Wet powder processing of sol-gel derived mesoporous silica-hydroxyapatite hybrid powders

This paper describes a method by which a porous silica coating layer can be obtained on different apatite particles through a simple sol-gel synthesis route. Sol-gel derived powders of hydroxyapatite (HAP) and beta tricalciumphosphate (beta-TCP) were coated with a mesoporous silica using C16TAB (hexadecyltrimethylammonium bromide) as a template in order to induce mesophase formation. Further calcination of the material removes the template from the mesophase and leaves a highly ordered hexagonal arranged mesoporous silica structure with a core of HAP/beta-TCP. The phase purity of the SiO2/apatite composites has been thoroughly investigated by the means of FT-IR, XRD, and solid state 31P MAS NMR. The phase purity of these materials is shown to be dependent on the solubility properties of the used apatites. The hybrid materials are suitable as a multifunctional biomaterial where osteoconductive properties can be combined with drug delivery.     

溶胶-凝胶技术制备光化学杂化材料

溶胶 -凝胶技术是制备有机 -无机杂化材料的重要手段 ,在光致变色、光纤传感和发光等光化学杂化材料制备方面应用前景广阔。提高光致变色染料的稳定性、制备溶胶 -凝胶光纤及降低杂化材料羟基含量是目前的研究重点。     

Preparation of highly ordered Fe-SBA-1 and Ti-SBA-1 cubic mesoporous silica via sol-gel processing of silatrane

Silatrane prepared from fumed silica and triethanolamine (TEA) was used as a precursor for the sol-gel synthesis of M-SBA-1 (M = Fe and Ti) at room temperature using cetyltrimethylammonium bromide as a template, and dilute solutions of ferric chloride and titanium glycolate as metal sources. Powder X-ray diffraction (XRD) showed the mesoporous materials to be well-ordered cubic structures, while N₂ adsorption/desorption measurements yielded high surface areas. Diffuse reflectance UV-visible spectroscopy demonstrated that iron (Fe³⁺) and titanium (Ti⁴⁺) were incorporated in the framework of the calcined materials to loadings of 6 wt.% Fe and 10 wt.% Ti without perturbing the ordered mesoporous structure.     

无机-有机复合膜应用的研究进展

介绍了近年来发展较快的无机—有机复合膜的研究情况，对其应用领域进行了综述并对将来的发展方向提出了一些看法．     

Preparation and characterization of PLZT thin films by sol-gel processing

The effect of acid catalysts on the sol-gel preparation of ferroelectric lead lanthanum zirconium titanate (PLZT) thin films was studied. High quality thin films were successfully produced by using suitable amounts of the drying control chemical additive formamide and also catalyst acids during the sol-gel processing followed by various annealing conditions. The dielectric constants of the PLZT (8/65/35) thin films produced in this study varied between 540 (100 kHz) for a film annealed at 600 °C for 30 mins to a maximum 870 °C (1 kHz), 700 (100 kHz) for a film annealed at 650 °C for 20 mins.     

Preparation and electro-optic properties of hybrid sol-gel films containing imidazole chromophore

An alkoxysilane precursor based on imidazole chromophore, namely 2-((4-(ethyl(2-hydroxyethyl)amino)phenyl)diazenyl)-4,5-dicyano-1H-imidazole (IZ), has been successfully synthesized through a urethane forming reaction. Following a sol-gel process of the resultant precursor, inorganic-organic hybrid films were obtained by spin-coating. Their structures were verified by ¹H NMR, FT-IR, UV-vis spectra and elemental analysis. After corona poling, the electro-optic (EO) properties of the hybrid films were characterized by a simple reflection technique, and the EO coefficient (r₃₃) of a sample was determined to be 1.6 pm/V at a wavelength of 1310 nm.     

Preparation and characterization of epoxy-silica hybrid materials by the sol-gel process

A transparent organic-inorganic epoxy/silica hybrid material was prepared by epoxy resin, functionalized-epoxy resin, which was partially functionalized by 3-aminopropyl triethoxylsilane(APTES), and highly reactive polysilcic acid (PSA), which was prepared through hydrolysis and condensation of metasilicate salt. The properties of hybrid materials such as impact strength, tensile strength, glass transition temperature (T_g), thermogravimetric temperature (TGA), and thermal effect of the hybrid materials were studied. The size of PSA particles in THF measured by dynamic light scattering technique, ranged from 10–28 nm. The results of experiment indicated that modified epoxy resin possed better roughness than that of the pure epoxy resin. The structure of the hybrid materials was characterized by FT-IR spectroscopy and 29SiNMR spectroscopy.     

Preparation of bioactive glass-polyvinyl alcohol hybrid foams by the sol-gel method

A new class of materials based on inorganic and organic species combined at a nanoscale level has received large attention recently. In this work the idea of producing hybrid materials with controllable properties is applied to obtain foams to be used as scaffolds for tissue engineering. Hybrids were synthesized by reacting poly(vinyl alcohol) in acidic solution with tetraethylorthosilicate. The inorganic phase was also modified by incorporating a calcium compound. Hydrated calcium chloride was used as precursor. A surfactant was added and a foam was produced by vigorous agitation, which was cast just before the gel point. Hydrofluoric acid solution was added in order to catalyze the gelation. The foamed hybrids were aged at 40 ^∘C and vacuum dried at 40 ^∘C. The hybrid foams were analyzed by Scanning Electron Microscopy, Mercury Porosimetry, Nitrogen Adsorption, X-ray Diffraction and Infra-red Spectroscopy. The mechanical behavior was evaluated by compression tests. The foams obtained had a high porosity varying from 60 to 90% and the macropore diameter ranged from 30 to 500 μ m. The modal macropore diameter varied with the inorganic phase composition and with the polymer content in the hybrid. The surface area and mesopore volume decreased as polymer concentration increased in the hybrids. The strain at fracture of the hybrid foams was substantially greater than pure gel-glass foams.     

Preparation of glass-nickel microcomposites byin situ reduction via sol-gel route

Gel has been prepared with nickel chloride and glucose in the starting solution followed by heat treatment at higher temperature, where glucose decomposes to carbon and water vapour, which in turn react to form hydrogenin situ to reduce nickel chloride to metallic nickel. The presence and distribution of nickel granules in the microcomposite, has been established by transmission electron microscopy, selected area diffraction and electron paramagnetic resonance analysis.