Development of Ion Sensors Based on Organic-Inorganic Composite as Membrane Materials

本研究以有机-无机复合材料为膜材料，构建了离子传感器。选择溶胶-凝胶玻璃和介孔二氧化硅两种材料作为膜材料用于离子传感器。1.基于溶胶-凝胶衍生膜的硫酸根离子传感器合成了带有三乙氧基硅基和硫脲基的化合物（1）。将化合物1加入到正硅酸乙酯（TEOS）和二甲基二乙氧基硅烷（DEDMS）的混合物中，通过水解、脱水和缩合，制备了化合物1化学改性的溶胶-凝胶膜。电极对硫酸根离子活性变化没有反应。另一方面，在使用硅橡胶作为膜材料的情况下，电动势响应几乎是能斯特的。2.基于溶胶-凝胶衍生膜的钙离子传感器合成了带有两个醚-酰胺基团和长的带有双键的烷基链的化合物（2），在化合物2中引入两个三乙氧基甲硅烷基（3）制备包封化合物2并用化合物3化学改性的溶胶-凝胶衍生膜。两种膜电极对钙离子活度的变化均表现出能斯特响应。3.以正硅酸乙酯、十六烷基三甲基溴化铵和16-冠-5衍生物为载体，制备了介孔二氧化硅离子传感器。将粉末状产物加入到正硅酸乙酯和二乙撑二甲基硫醚的混合物中，通过溶胶-凝胶法制备了介孔二氧化硅膜。膜电极在较高的钠离子活度范围内表现出近能斯特响应。

In this study, ion sensors, which are based on organic-inorganic composite as membrane materials, were constructed. Two types of materials, sol-gel glass and mesoporous silica, were selected, and used for ion sensors as membrane materials.1.Sulfate ion sensors based on sol-gel derived membranesThe compound bearing a triethoxysilyl group and a thiourea group (1)was synthesized. Sol-gel derived membranes modified chemically with compounds 1 were prepared, by adding compound 1 into the mixture of tetraethoxysilane (TEOS) and diethoxydimethylsilane (DEDMS), through their hydrolysis, dehydration, and condensation. The electrodes did not respond to sulfate ion activity changes. On the other hand, in the case that silicone rubber was used as a membrane material, the EMF responses were almost Nernstian.2.Calcium ion sensors based on sol-gel derived membranesThe compound bearing two ether-amide groups and long alkyl chains with double bonds (2)was synthesized, and then, two triethoxysilyl groups were introduced into compound 2 (3)Sol-gel derived membranes encapsulating compound 2 and modified chemically with compounds 3 were prepared. Both membrane electrodes showed Nernstian responses to calcium ion activity changes.3.Ion sensors based on mesoporous silicaTEOS, cetyltrimethylammonium bromide, and 16-crown-5 derivative bearing a triethoxysilyl group were used, in order to prepare mesoporous silica which was chemically modified with ionophores. The powdery product was added into the mixture of TEOS and DEDMS, and, therefore, mesoporous silica membranes were formed by sol-gel method. The membrane electrodes showed near-Nernstian responses at higher range of sodium ion activities.