Development of materials with ordered structure through phase separation of inorganic-organic mixed sol-gel system

通过无机-有机混合溶胶-凝胶体系的相分离开发有序结构材料

• 批准号: 02555161
• 负责人: SOGA Naohiro
• 金额: $ 9.02万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02555161/
• 关键词: Sol-gel method; Alkoxysilanes; Organic polymer; Spinodal decomposition; Light scattering measurements; Solvent exchange; Nitrogen adsorption measurements; ゾル-ゲル法

A method of preparing silica gels with micrometer-range inte-rconnected pores by hydrolyzing alkoxysilanes under coexistence of water-soluble polymers has been investigated in detail. Following results have been obtained ;1. Many kinds of water-soluble polymers that have substantial solubility in--water-alcohol mixed solvent can be used in the process.2. Hydrolysis of alkoxysilanes under strongly acidic condition is favored but polycondensation may be conducted also under more basic condition.3. Light scattering profiles of gelling solution exhibited first a continuous development of concentration fluctuation with a fixed periodic wavelength, second a parallel increase of fluctuation and periodic wavelength, and finally a fixation of periodic wavelength and further increase of concentra tion difference. These changes indicate a concurrent occurrence of spinodal decomposition and sol-gel transition in the reacting system.4. Morphology of gels can be controlled by changing starting composition and reaction temperature. Reaction conditions which make a phase separation to occur earlier relative to a sol-gel transition result in coarse morphologies and vice versa. Polymers with high solubility in water-alcohol mixed solvent are favored to obtain gel morphologies with better reproducibility.5. By exchanging solvent phase in wet gels with micrometer-range interconnected pores, the volume and distribution of nanometer-range pores can be, modified to a large extent. This process enables one to tailor pore structure of gels both in micrometer- and nanometer-ranges.

本文详细研究了在水溶性高分子共存下，烷氧基硅烷水解制备微米级连通孔硅胶的方法。取得了以下研究成果：1.在水-醇混合溶剂中有很大溶解度的多种水溶性聚合物可用于该工艺.烷氧基硅烷在强酸性条件下的水解是有利的，但缩聚也可以在更碱性的条件下进行。胶凝溶液的光散射曲线表现为：浓度波动随周期波长的固定而不断发展;浓度波动随周期波长的平行增加;浓度波动随周期波长的固定而进一步增加。这些变化表明反应体系中同时发生了调幅分解和溶胶-凝胶转变.通过改变起始组成和反应温度可以控制凝胶的形态。使相分离相对于溶胶-凝胶转变更早发生的反应条件导致粗糙的形态，反之亦然。在水-醇混合溶剂中溶解度高的聚合物有利于获得重现性好的凝胶形态.通过在具有微米级连通孔的湿凝胶中交换溶剂相，可以在很大程度上改变纳米级孔的体积和分布。该过程使人们能够在微米和纳米范围内定制凝胶的孔结构。

项目成果

Hideki Matsuoka: "Small-angle X-ray scattering study on sol-gel transition of mixtures of colloidal silica and organic polymer" Bulletin of Chemical Society of Japan. 64. 1283-1288 (1991)

松冈秀树：“胶体二氧化硅和有机聚合物混合物溶胶-凝胶转变的小角X射线散射研究”日本化学会会刊。

Kazuki Nakanishi: "Phase separation in silica sol-gel system containing polyacrylic acid.IV.Effect of chemical additives" Journal of Non-Crystalline Solids.

Kazuki Nakanishi：“含有聚丙烯酸的二氧化硅溶胶-凝胶体系中的相分离。IV.化学添加剂的影响”非晶固体杂志。

Kazuki Nakanishi: "Dual porosity silica gels by polymer-incorporated sol-gel process" Journal of Non-Crystalline Solids.

Kazuki Nakanishi：“通过聚合物掺入溶胶-凝胶工艺制备双孔隙硅胶”《非晶固体杂志》。

Norio Nemoto: "Diffusion of a dye-labeled cetyldimethylamine incorporated in rodlike micelles of cetyltrimethylammonium bromide in aqueous sodium salicylate solutions" Langmuir. 7. 2607-2613 (1991)

Norio Nemoto：“染料标记的十六烷基二甲胺掺入十六烷基三甲基溴化铵在水杨酸钠水溶液中的棒状胶束中的扩散”Langmuir。

Kazuki Nakanishi: "Phase separation in silica sol-gel system containing polyacrylic acid I.Gel formation behavior and effect of solvent composition" Jounal of Non-Crystalline Solids. 139. 1-13 (1992)

Kazuki Nakanishi：“含有聚丙烯酸 I 的二氧化硅溶胶-凝胶体系中的相分离。凝胶形成行为和溶剂成分的影响”非晶固体杂志。