表面活性物质对SiO_2干凝胶中甲基橙变色反应的影响  

Effects of Surface-Active Substances on Methyl Orange Reactivity in SiO_2 Xerogels

作　　者：吴志坚[1] 兰心仁[1] 林岩心[1] 黄理耀[1] 

机构地区：[1]华侨大学材料科学与工程学院,泉州362011

出　　处：《应用化学》2003年第3期228-232,共5页Chinese Journal of Applied Chemistry

基　　金：国务院侨办科研基金;福建省青年科技人才创新基金 ( 2 0 0 1J0 2 3)资助项目

摘　　要：以硅酸乙酯 (TEOS)为主要原料用溶胶 凝胶法制备了十六烷基三甲基溴化铵 (CTAB)、十二烷基硫酸钠 (SDS)和硬脂酸 (SA)调制的含甲基橙 (MO)的SiO2 干凝胶 ,用红外光谱和热重分析对凝胶进行了表征 ,研究了凝胶中甲基橙变色点的变化以及在 pH值分别为 1 0、7 0和 13 0的溶液中凝胶中甲基橙的渗出情况。实验结果表明 ,凝胶中的甲基橙变色范围不明确 ,只能大致确定其变色点。CTAB掺杂的凝胶中甲基橙的变色点的 pH值明显移向低 pH值 ,低于无表面活性物质及SDS和SA调制凝胶变色点的pH值 ,而这些凝胶的变色点pH值接近。SDS掺杂的凝胶中甲基橙的渗出率明显高于其它样品 ,在不同pH值水溶液中 7d后的渗出率都在 3 0 %以上 ,CTAB掺杂的凝胶中甲基橙的渗出率在酸性和中性水溶液中 7d后低于 0 0 5 %。Methyl orange(MO) doped SiO 2 xerogels derived from tetraethyl orthosilicat e(TEOS) and modified with cetyltrimethylammonium bromide(CTAB), sodium dodecyl sulfate(SDS) and stearic acid(SA) respectively, we re prepared. FTIR and TG analyses were used to characterize the xerogels. The co lor change and leaching behavior of MO in the xerogels were investigated. Th e experimental results show that MO in the xerogels has no definite pH value color change. The color change pH values of MO in the xerogel doped with CTAB s hift to low pH values, and are lower than those of MO in the other surfactant do ped xerogels. The xerogel doped with SDS shows the highest leaching rate of MO. The leaching rates in solutions of different pH values after 7 days are all higher than 30%. The leaching rate of MO in the xerogel doped with CTAB is the l owest, and the leaching rate in acidic and neutral solutions after 7 days is low er than 0 05%. The results have been discussed.

关 键 词：表面活性物质 SiO2干凝胶 甲基橙 变色反应 掺杂 二氧化硅 

分 类 号：O648.17[理学—物理化学]