溶胶-凝胶法原位生成 SiO2增强 EPDM

利用溶胶－凝胶法原位聚合四乙氧基硅烷生成SiO_2增强EPDM。TEM观察显示原位SiO_2均匀地分散在硫化胶中,而且粒径在15 nm以下。TGA测试表明,初步的研究引入了3.6％的原位SiO_2。硫化胶的拉伸强度和定伸应力被提高了近2倍。     

溶胶-凝胶法制备SiO2减反膜研究

抗反射涂层(减反膜)在军事、日常生活、工业等各领域有广泛应用。特别是对高能激光系统(惯性约束核聚变至关重要的技术之一)有重要意义。文章分析了减反膜的光学原理,介绍了其常用制造材料二氧化硅(SiO₂)的特性。论述了溶胶-凝胶法制备减反膜的原理及独特优点,描述溶胶-凝胶法镀制减反膜的过程,即通过反应制得SiO₂前驱待镀膜溶胶,再经由浸涂、旋涂、喷涂与涂布等方式镀制减反膜。分析了前体溶胶中各种化学反应过程,及反应中各因素对SiO₂材料和最终镀制减反膜的影响。最后叙述了溶胶-凝胶法制备减反膜的新进展,如向溶胶中加入添加剂、改造待镀膜材料以及与其他制备减反膜的方法联合改性等方法。这样制得的减反膜不仅增强了膜的光学性能还使之具有了如自清洁等功能。最后展望了其在光伏、LED照明与多种前沿技术领域的应用。     

原位溶胶-凝胶法改性EPDM及其表征

采用原位溶胶-凝胶反应制备乙丙橡胶/ SiO₂纳米复合材料。分别以乙丙橡胶（EPDM）和γ-甲基丙烯酰氧丙基三甲氧基硅烷（KH570）接枝改性的乙丙橡胶 （EPDM-g-KH570）在前驱体四乙氧基硅烷 （TEOS）中溶胀,再浸入含有正丁胺的催化剂溶液中催化前驱体的原位溶胶-凝胶反应。考察了不同溶剂以及催化剂含量对TEOS转化率和原位生成的SiO₂粒径的影响。采用FT-IR、SEM等测试手段对纳米复合材料进行了表征。结果表明,接枝KH570后,TEOS转化率明显提高,SiO₂粒径明显减小,在材料中的分散性很好。     

用溶胶—凝胶法原位生成SiO2增强橡胶

介绍了用溶胶－产法原位生成ＳｉＯ２纳米粒子增强橡胶的技术,以及该技术的３种不同方法：（１）在硫化胶中生成原位ＳｉＯ２;（２）在非硫化胶中生成原位ＳｉＯ２;（３）在硫化反应中生成原位ＳｉＯ２。同时对溶胶－凝胶技术的反应原理和影响因素作的探讨。总结了原位ＳｉＯ２增强橡胶复合材料的结构特征（粒径及其分布、分散性、界面状态）主由此导致的物理机械性能。分析了这种技术的优缺点及其在橡胶工业中的应用前景。     

溶胶-凝胶法制备PTFE/SiO2疏水涂层

以聚四氟乙烯乳液(PTFE)和纳米硅溶胶为主要原料通过溶胶-凝胶法在玻璃表面上制备了疏水涂层。水滴在表面的接触角达到126°。通过显微电镜观察涂层表面结构,发现涂层表面分布许多微米大小的乳突。聚四氟乙烯低的表面能和复合表面的微米乳突结构是涂层能形成良好疏水性能的原因。考察了聚乙烯醇对复合涂层疏水性的影响。     

溶胶-凝胶法与自模板法相结合制备SiO2中空微球

以正硅酸乙酯和甲基三甲氧基硅烷为硅源,采用sol-gel法制备SiO2胶体粒子,作为制备中空微球的前体,然后在固化剂的作用下,利用自模板法使乳液液滴外表面首先被固化,并以其自身作为模板制备SiO2中空微球,讨论了去离子水用量和搅拌速率对微球尺寸的影响。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、动态光散射(DLS)和低温氮吸附法对其进行表征。结果表明,得到的SiO2中空微球球形形态规整,平均粒径为592nm,其表面具有微孔/介孔复合结构,且在一定的范围内,微球的尺寸随着去离子水用量和搅拌速率的增加而逐渐减小。     

溶胶-凝胶法制备纳米二氧化硅

本文通过溶胶一凝胶法制备纳米SiO2。考察了不同温度、pH值、催化剂对制备纳米SiO2的影响。并运用了TEN表征了纳米SiO2的粒径大小、分散度以及粒子性状，得出了制备纳米SiO2较好的工艺条件。     

溶胶-凝胶法制备SrBi2Ta2O9(SBT)铁电薄膜的研究

以乙醇钽、醋酸锶和硝酸氧铋为原材料,乙二醇单甲醚为溶剂,可以获得稳定的SBT溶胶和凝胶.采用Pt/Ti/SiO     

溶胶-凝胶法Al2O3涂层工程陶瓷抗弯强度的数学解析

应用数学方法分析了Al     

溶胶-凝胶法制备TiO2纳滤膜的研究

无机纳滤膜因其耐酸碱,化学和热稳定性优于有机纳滤膜,受到广泛的关注。采用溶胶-凝胶法制备TiO2无机纳滤膜,以钛酸丁四酯为前驱体,以乙酰丙酮为抑制剂,利用单因素实验方法研究了加水量、无水乙醇量、溶液的pH值和反应温度对TiO2溶胶的影响,从而确定了制备TiO2溶胶的最佳方案。并分析有机添加剂PVA加入量对凝胶和成膜效果的影响。     

溶胶-凝胶法制备纳米二氧化硅微球的研究

采用溶胶-凝胶法制备纳米二氧化硅,通过傅里叶红外光谱表征成分,用800倍数码显微镜观察表面形貌,探讨不同反应条件对纳米二氧化硅表面形貌的影响。纳米二氧化硅微球在不同溶剂中的分散性。结果表明,在酸、碱条件下,分别生成纳米二氧化硅溶胶和纳米二氧化硅微球;碱性条件下,反应温度和反应时间分别为40℃和4 h时,纳米二氧化硅微球呈现规整、均一的球型形貌;纳米SiO_2微球在有机溶剂中的分散性都较好,且分散均匀。     

Double phase separation in preparing polyimide/silica hybrid films by sol-gel method

In this paper, the phase separation process of the polyimide/silica hybrid films made from polyamic acid (PAA) and precursor (TEOS-A) hydrolyzed tetraethoxysilane under acidic condition in N-methyl-2-pyrrolidone (NMP) through sol-gel method was investigated by the scanning electron microscope (SEM). A double phase separation was discovered for the preparation of the hybrid films. With evaporation of the solvent NMP at lower than 100 °C, the component miscibility of TEOS-A and PAA decreases so that the first phase separation took place and a larger particle phase of TEOS-A precursor with size around 2.0 μm was formed. The second phase separation from the matrix phase appeared, as PAA was imidized at elevated temperature, which destroyed the interaction between carboxyl group of PAA and hydroxyl group of TEOS-A, and a nanoscale SiO₂ particle phase formed. The formation mechanism of the double phase separation was explained by the “capture-release” model. According to the model, the second phase separation can be controlled by synthesizing amic acid-imide copolymer with different contents of carboxyl group.     

In-situ precipitation of reinforcing titania fillers

Summary The technique developed for precipitating reinforcing silica into an elastomer is extended to titania fillers by hydrolyzing a titanate instead of a silicate. Of the three catalysts studied, namely HCl, NH₄OH, and (C₂H₅)₂NH, the NH₄OH was the most efficient, introducing as much as 65 wt % titania into a poly(dimethylsiloxane) network in twelve hours. Stress-strain measurements in elongation showed the nature and extent of the reinforcement to be very similar to that obtained from insitu precipitated silica.     

溶胶-凝胶法制备二氧化硅包覆水性C.I.P R 31

以3-氨基-4-甲氧基苯甲酰苯胺(RBKD)和3-羟基-N-(3-硝基苯基)-2-萘甲酰胺(NASBS)为中间体,通过重氮化和偶合反应,制备了单偶氮红色系C.I.PR31。偶合过程中首先选用松香酸对其进行水性化改性处理,进而通过溶胶-凝胶法在颜料表面包覆了1~3层的SiO_2颗粒层。经接触角、SEM、TEM、色光、热重分析测试,结果表明:经过松香酸处理的颜料样品晶体形貌可由长条状转变为圆片状,极性明显增强。松香酸占总反应物质量的3%时,颜料与水之间的接触角降至52.8°,粒径分布峰值和粒径分布宽度分别降至78 nm和0.01~0.54μm,具有较佳的亲水性能。包覆2层及2层以上的SiO_2可使颜料接触角降至0,完全转为亲水性。松香酸的加入在一定程度上会导致颜料色样偏向红色和蓝色,而SiO_2颗粒层则使颜料偏向绿色和蓝色。包覆2层SiO_2的C.I.PR31*-2SiO_2色差(ΔE)为0.96,着色力可达105.09%,氮气气氛中加热至290℃颜料晶体开始分解,达到了耐高温颜料的标准,可以用于水性分散介质。     

Pore size control of porous silica by sol-gel process

Porous silica glass was prepared by sol-gel process from tetraethoxysilane (TEOS). The effects of solvents (water, ethanol), drying condition, heat treatment temperature on specific surface area and pore size distribution of porous silica were investigated. Gelation process accelerates with an increase of H₂O content, while retards with the increase of ethanol amount. Structure changes during heat treatment were studied by means of DTA, XRD. TEM micrographs show that the gel particles shrink after heated at 500°C, thus the average pore size decreases.     

sol-gel法制备微孔SiO2分离膜的研究进展

微孔SiO2分离膜在气体分离、催化、膜反应器等领域有着巨大的应用潜力。本文首先简要介绍了获得微孔的两种途径，然后重点对sol—gel法制备微孔SiO2分离膜的研究进展进行综述。     

Corrosion inhibition of magnesium by combined zirconia silica sol-gel films

The inhibition of Mg (AZ91D) corrosion by thin sol-gel films was studied. The sol-gel films were prepared by the traditional acid or base-catalyzed hydrolysis and condensation, and finally deposited by dip coating. Two different sol-gel monomers were used: phenyltrimethoxysilane (PTMOS) and zirconium(IV)tetra-1-propoxide (ZrTPO). Films were made of each of the individual monomers and by depositing first a PTMOS film followed by ZrTPO-based film. The corrosion inhibition of the films and their characterization were examined by different methods including potentiodynamic polarization, contact angle measurement, adhesion test, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS).We found that while the ZrTPO-based film did not show a significant corrosion inhibition, the PTMOS-based film provided moderate protection. Interestingly, the combined film exhibited superior corrosion inhibition as compared with the other films.     

Organically functionalized sol-gel silica network growth

The detailed information about the growth of organically modified silica networks regarded as useful for barrier coatings and membrane coatings preparation are the subject of this paper. The networks obtained using different precursors containing non-hydrolysable organic groups: dimethyldiethoxysilane – dMdEOS, ethyltriethoxysilane – EtEOS, n-propyltriethoxysilane – nPtEOS have been investigated with rheology and Raman spectroscopy of solutions. The polycondensation degree during aging has been calculated. Individual networks have been monitored for selected points during 654 h of aging. Thanks to the completion of rheology and Raman spectroscopy investigations different influence of aging and physicochemical interaction occurring in particular sols and influencing their rheological behavior have been revealed. The observed differences also apply to the type of structures created by hydrolysis and condensation reaction and are connected with organic group functionalizing silica network.