季铵盐阳离子双子表面活性剂C_(12)-2-C_(12)·2Br与HPC在水溶液中的相互作用

Interactions between Quaternary Ammonium Gemini Surfactant C_(12)-2-C_(12)·2Br and Hydroxypropyl Cellulose in Aqueous Solution

采用流变和荧光等方法研究了季铵盐阳离子双子表面活性剂C12-2-C12·2Br（S2）与水溶性高分子羟丙基纤维素（hydroxypropyl cellulose HPC）质量分数1％的水溶液的相互作用。HPC／S2水溶液在剪切速率r=0～700s^-1内均表现为牛顿型。混合溶液η0随着表面活性剂浓度的增加开始升高，在表面活性剂浓度约2．0mmol·L^-1时出现峰值，然后呈缓慢下降趋势。稳态荧光测定，I1／I3及电导测定电导率随S2浓度变化的结果表明：HPC／S2水溶液中两者相互作用，S2在HPC分子上形成了聚集体，临界聚集浓度为0．7mmol·L^-1，到2．0mmol·L^-1时溶液中自由胶团生成。

An experiment was eondueted to study the interactions between the quaternary ammonium gemini surfaetant C12-2-C12·2Br （S2 ） and hydroxypropyl eellulose （HPC） in aqueous solution by steady-state fluoreseenee as well as rheological experiments. S2/HPC aqueous solution kept Newtonian flow through out the range of shear rote from 0 to 700 s^-1. The zero-shear viseosity η0 of S2/HPC aqueous solution first increases with S2 eoneentrations ranging from 0 to 2 mmol · L^-1 , and then ehanges slightly when S2 is higher than 2 mmol · L^-1. Fluoreseenee quenehing experiments show that the presence of HPC induces the aggregation of S2 at eoneentrations lower than the eritieal mieelle eoneentration of S2 itself. Mieelle-like S2 clusters bound to HPC. Critieal aggregation eoneentration of S2 （ CS2 ） is 0.7 mmol · L^-1 in the S2/HPC aqueous solution. Free mieelles of S2 formed at a eoneentration of CS2 higher than 2 mmol · L^-1 .