水在C12-EOx-C12•2Br/正己醇/正庚烷W/O微乳中的状态

以FT-IR方法研究了水/C₁₂-EO_x-C₁₂?2Br/正己醇/正庚烷形成的W/O微乳中水的状态. 结果表明, 其中的水存在4种状态, 分别为阳离子头基结合水、反离子结合水、类似本体的水以及束缚在微乳栅栏层中的水. 由解卷积技术分解FT-IR谱图, 进而获得每个表面活性剂分子对应于这4种状态水分子的数目n_N＋, n_Br-, n_b和n_f. 随着水含量(W₀)增加, n_b急剧增大, n_N＋少许上升, 而n_f和n_Br-维持不变, 这说明微乳水核逐渐长大, 且在所考察W₀范围内, 表面活性剂头基解离度保持不变.

States of Water in the W/O Microemulsion Formed in H2O/C12-EOx-C12•2Br/n-Hexanol/n-Heptane

The states of water in the W/O microemulsions formed in H₂O/C₁₂-EO_x-C₁₂?2Br/n-hexanol/ n-heptane systems have been investigated by Fourier transform infrared spectroscopy (FT-IR). The results showed that there existed four states of water in the microemulsions, which were head-group-bound water, Br^--bound water, bulklike water and trapped water in the interface of the microemulsion water, respectively. The n_N＋, n_Br-, n_b and n_f, which represented respectively the numbers of the water corresponding to the above four states per surfactant molecule, were obtained by a deconvolution technique. With increasing water content W₀, n_b was increased rapidly but n_N＋ increased a little, whereas n_Br- and n_f were kept almost constant. These indicated that the water pool of the microemulsion grew gradually and the degree of the counter-ion dissociation was kept unchanged over the range of the ex-amined W₀.