Triton X-100/n-C~4H~9OH/H~2O体系的扩散系数与结构特性

在无外加探针条件下用循环伏安法测定了不同形状TritonX-100胶束的扩散系数,得到第一cmc(临界胶束浓度)为3.1×10^-^4mol.L^-^1,第二cmc为1.3×10^-^3mol.L^-^1,并给出了TritonX-100的电化学反应机理。随正丁醇含量的增加,TritonX-100球形胶束的扩散系数迅速增加,正丁醇的增溶分数略有降低,但胶束内微极性却降低较多;棒状胶束转变为球形胶束,正丁醇的增溶分数基本不变,但胶束内微极性降低。随温度升高,TritonX-100分子与胶束的扩散系数均增加。正丁醇含量<1.5%时,扩散活化能E~D随正丁醇含量增加而迅速增加;但正丁醇含量>1.5%时,E~D增加变缓。

Diffusion coefficient and structure properties of Triton X-100/n- C~4H~9OH/H~2O system

The diffusion coefficient of Triton X-100 of different shape is determined by cyclic voltammetry without any probe. The first cmc (3. 1×10^-^4mol.L^-^1) and the second cmc (1.3 ×10^-^3mol.L^-^1) are obtained. The mechanism of electrochemical reaction for Triton X-100 is deduced by cyclic voltammetry, FT-IR spectrum, reaction at RRDE and pH measurement. When n-butanol is added, the diffusion coefficient of spherical micelles increases rapidly. The solubilization fraction of n-butanol decreases a little, but the micropolarity in spherical micelles decreases more. On the other hand, rodlike micelles change into spherical micelles, and the solubilization fraction of n-butanol is almost constant. The micropolarity in rodlike micelles, however, decreases when the n- butanol is added. Furthermore, the diffusion coefficient increases with temperature, and diffusion activation energy increases with n- butanol content.