Effect of Steric Hindrance on the Aggregation Behavior of Cationic Silicone Surfactants in Aqueous Solutions
作者:Jinglin Tan、Ziyan He、Yongxiang Miao、Dezhi Zhou
DOI:10.1007/s10953-019-00888-w
日期:2019.6
the steric hindrance of hydrophobic groups and headgroups, the CMC values increase following the order Vi–Si4pyrCl < Si4AEtCl < Si3pyrCl. The micellization process of Si3pyrCl and Si4AEtCl in aqueous solution is enthalpy-driven, while Vi–Si4pyrCl is entropy-driven at low temperature and enthalpy-driven at high temperature and the degree of counterion binding of Vi–Si4pyrCl increases as the temperature
研究空间位阻对阳离子有机硅表面活性剂的表面活性和热力学的影响,不同硅氧烷疏水基团和头基的阳离子有机硅表面活性剂的吸附和聚集行为,双(三甲基甲硅烷氧基)甲基甲硅烷基丙基氯化吡啶(Si3pyrCl),N,N,N -三乙基-3-[三(三甲基甲硅烷氧基)]甲硅烷基丙基氯化铵(Si4AEtCl)和3-[三(乙烯基二甲基甲硅烷氧基)甲基]甲硅烷基丙基氯化吡啶鎓(Vi-Si4pyrCl),通过表面张力、电导率、DLS、TEM和2D进行了研究NOESY NMR 测量。这三种阳离子有机硅表面活性剂均具有优异的表面活性。由于疏水基团和头部基团的空间位阻,CMC 值按照 Vi-Si4pyrCl < Si4AEtCl < Si3pyrCl 的顺序增加。Si3pyrCl 和 Si4AEtCl 在水溶液中的胶束化过程是焓驱动的,而 Vi-Si4pyrCl 在低温下是熵驱动,在高温下是焓驱动,并且 Vi-Si4pyrCl