正硅酸乙酯膜固色研究

研究正硅酸乙酯-乙二醇溶胶成膜固色,溶胶与纤维间是物理吸附,不受化学键的干扰,在纯棉黑色织物上成胶后,干摩擦牢度为3～4级,湿摩擦牢度为2～3级,且织物的风格不受影响,色泽鲜亮手感柔软,但耐洗性尚待研究.     

硅溶胶-膨润土法澄清大蒜多糖提取液的研究

为找出一种既经济又快速的澄清大蒜多糖提取液的方法,以透光率、沉淀率、考马斯亮兰反应为指标,评价不同的pH值、不同酸性硅溶胶和膨润土用量对大蒜多糖提取液的澄清效果,然后选用效果较好的因素水平做正交实验。结果表明:在pH4的环境下,加入0.1%酸性硅溶胶和0.2%膨润土,可除去蛋白质等杂质。     

溶胶制备工艺对直接黑GF的Sol-Gel法固色影响

用γ-缩水甘油醚氧丙基三甲氧基硅烷(GPTS)制备水溶胶，将溶胶-凝胶法应用于直接黑GF染色织物的固色处理。讨论了溶胶制备工艺对固色效果的影响。结果表明，采用浓度为1：50，在室温和pH=4的条件下搅拌2h～2．5h制备的溶胶能达到较理想的固色效果和一定程度的洗涤增深效果。     

Fluidized state gelation of ceramic microspheres: Feasibility study of a continuous process and analysis of the chemical dehydration phenomena

A continuous gelation process for producing aluminum and zirconium hydroxide microparticles was conceived and tested in a lab‐scale apparatus. Fluidized state was devised as an appropriate hydrodynamic configuration to maintain the reacting sol microdrops suspended: stable non‐coalescing spherical gel particles in a size range quite below 100 μm were produced via gelation. The microspheres produced by a subsequent calcination step showed a diameter ranging between 2 μm and 20 μm. This powder, without further size classification, was an optimal product to manufacture test specimens by sintering. Measurements on the mechanical properties, such as toughness, flexural strength and hardness, classified the test bars as a very promising ceramic material. In order to enlighten the chemical drying phenomenon and devise the main governing mechanisms acting in the gelation reaction, an extremely simplified experimental system was set. A single drop of sol was deposited into a given amount of the dehydrating liquid medium and observed by an optical microscope; image analysis permitted us to identify the gel formation, the size reduction kinetics, as well as secondary phenomena.     

A parametric study of visible-light sensitive TiO2 photocatalysts synthesis via a facile sol–gel N-doping method

In the present work, a parametric study of visible-light sensitive TiO₂ via a facile sol–gel N-doping method was carried out. Visible-light activity of as-prepared products was assessed using solutions of methylene blue as model pollutants. Optimal visible-light activity was achieved at equal N-to-Ti precursor molar ratio and 350 °C calcinations. Characterisation of structural, chemical and optical properties of synthesised TiO₂ photocatalysts was also undertaken to elucidate the effects of N-to-Ti precursor molar ratio and calcinations temperature on the resulting photocatalytic activity. The pH value of N-doped TiO₂ sol during the preparation was also found to be an effective indicator of N-doping quality without using any post-synthesis analysis. These findings could be utilised in the successful development of TiO₂ photocatalysts or their nanocomposites for cost effective solar irradiation-driven environmental technology.     

Molecular weight and concentration effects on gel/sol transitions in a segmented rigid-rod polyimide solution

Gel/sol and order/disorder transitions can be observed in a segmented rigid-rod polyimide solution at different concentrations and molecular weights. This polyimide was synthesized from 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl in refluxing 3-cresol in a one-step process. Above about 140°C, the polymers are completely soluble in 3-cresol in a concentration range up to 12(w/w)%. During cooling, the hot solutions undergo a mechanical sol/gel transition to form thermally reversible gels. In the gel state, an ordered structure develops. Both the gel/sol and order/disorder transitions are dependent upon concentration, temperature, and molecular weight, but the two transitions exhibit different kinetics. Possible mechanisms of these transitions are discussed.     

溶胶--凝胶与涂料

论述了国外硅系Sol-Gel之由来，研究动态及其应用领域。     

The properties of protective oxide scales containing cerium on alloy 800H in oxidizing and oxidizing/sulphidizing environments

The corrosion protection of oxide scales formed by electrophoretic deposition in a cerium-containing sol on Alloy 800H, a 32Ni-20Cr steel, followed by firing in air at 1123 K was studied in oxidizing and mixed oxidizing/sulphidizing environments at elevated temperatures. In particular, the influence of type of sol solvent, sol concentration, and thickness of deposited layer on the protection were studied. An optimized treatment was deduced which led to a significant improvement in corrosion behavior in oxidizing/sulphidizing environments.