可聚硼酸酯表面活性剂的表面化学性质及与LAS相互作用

用表面张力法研究了可聚合硼酸酯表面活性剂(BES)水溶液不同温度下(288-313 K)的表面活性和热力学函数变化；考察了BES与十二烷基苯磺酸钠(LAS)在0.5 mol·L-1 NaCl溶液中的相互作用. 结果表明, 298 K时, BES临界胶束浓度cmc达到0.066 mmol·L-1, γcmc为29.2 mN·m-1；在所考察的温度范围内BES胶束形成自由能(ΔG0m)在-22.4 - -25.8 kJ·mol-1之间, 胶束形成是熵驱动过程. BES/LAS混合体系为具有较大负偏差的非理想体系, BES/LAS分子间平均相互作用参数βm=-3.48；当溶液体相中BES摩尔分数αBES＝0.5时, 混合胶束中BES摩尔分数X1m为0.46, |βm|达到最大, 而且此时混合溶液cmc为0.017 mmol·L-1, 达到最低, γcmc为27.8 mN·m-1.

Surface Activity of a Novel Borate Ester Surfmer and Its Interaction with LAS in Aqueous Solutions

Using surface tension method, the changes of surface activity and thermodynamic properties of a novel borate surfactant surfmer (BES) in aqueous solution were studied at different temperatures (288-313 K). The interaction of BES with sodium dodecylbenzene sulfonate (LAS) in 0.5 mol·L-1 aqueous NaCl solutions was also measured. The results showed that the critical micelle concentration(cmc) of BES at 298 K was 0.066 mmol·L-1, and γcmc was 29.2 mN·m-1. The micellization free energie (ΔG0m) was in the range of -22.4 - -25.8 kJ·mol-1 at the experimental temperatures, and the process of micellization of BES was mainly driven by the entropy. The mixed BES/LAS solution was a non-ideal system with negative deviation, and the average molecular interaction parameter βm was -3.48. When the molar fraction αBES of BES in bulk solution was 0.5, its molar fraction X1m in mixed micelles was 0.46, |βm| could reach the maximum, cmc of the mixed solution reached the minimum 0.017 mmol·L-1, and γcmc was 27.8 mN·m-1.