Aerosol-OT在水和聚乙二醇-200混合溶液中有序结构转变及影响因素研究

通过电导、流变学方法等研究了温度和表面活性剂浓度对双(2-乙基己基)磺基琥珀酸钠(AOT)、水和聚乙二醇-200(PEG-200)体系有序结构形成和转变的影响。结果发现,在室温下高浓度AOT溶液中出现凝胶结构。当AOT的浓度为400mmol/kg以上时,随着温度的升高,观察到体系从透明粘稠到稍浑浊再到透明低粘度的过程,结合AOT的双链结构并通过流变实验验证了网络结构的形成,推测该体系在微观上经历了从凝胶到囊泡再到胶束的转变过程。当AOT的浓度为200~400 mmol/kg时,随着温度的升高,出现了凝胶和胶束混合体系到胶束体系的转变过程。

Effects of Temperature and Surfactant Concentration on the Aggregation of Aerosol-OT in PEG-200 and Water Mixed Solvent

Conductivity and rheological properties of aggregated behaviors of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in polyethylene glycol 200 (PEG 200) and water mixed solvent media are studied as a function of temperature and AOT concentration. The results show that the system appears network structure of gel at higher AOT concentration and at room temperature. For the system of AOT concentration over 400 mmol/kg, the solution is colorless, transparent and syrupy with no polarized behavior at low temperature, supposed the formation of gel; Then the solution changes a little turbid accompanied by the rapid increase of conductivity with increasing the temperature, indicating the appearance of vesicles; Temperature continues to rise, the solution changes transparent again. So, the AOT solution changes from gel to vesicles, and finally micelles as the temperature increases, and the process is reversible. While for the system of AOT concentration between 200 and 400 mmol/kg, the solution transforms from the coexisting system of gel-micelles to pure micelles system.