摘要
用流变学方法研究了pH对油酸钠/盐酸三乙胺（NaOA/Et3NHCl）蠕虫状胶束溶液流变性质的影响。通过稳态剪切和动态流变实验发现,30℃时,NaOA（0.12 mol/L）/Et3NHCl（0.2 mol/L）溶液在pH=8.20~9.40循环变化时,pH对溶液黏度的改变具有“开关”效应,可实现黏度在3~27 649 mPa·s时反复变化3次以上。体系在pH=8.55~9.02时为蠕虫状胶束,其流变行为符合Maxwell模型。这种溶液流变性对pH的响应行为是由于pH对反离子Et3NH＋与NaOA的相互作用影响而产生的。当pH降低时,反离子Et3NH＋的离子势增大,导致胶束表面电荷密度降低,蠕虫状胶束进一步增长。当pH=8.64,胶束因相互吸引而析出。而在初始条件下,升高pH=9.40,反离子Et3NH＋从胶束中解吸出来,蠕虫状胶束受到破坏。
The rheological behaviors of a pH-switchable wormlike micelles system formed by sodium oleate/triethylamine hydrochloride were investigated by rheology method. Steady-state and dynamic rheological measurements show that the viscosity of the NaOA（0. 12 mol/L）/Et3NHCI（0. 2 mol/L） solutions varied between 3 and 27 649 mPa · s more than three times without any deterioration to their responses when the system pH value ranged rheological behaviors comply with Maxwell and cycled between 8.20 and 9.40 at 30℃. These model. These pH-stimuli rheological properties were attributed to the effect of pH on the interaction between NaOA and its counterions Et3 NH＋. With the system pH decreasing, the counterions Et3 NH ＋ ionic strength lowered and the micellar surface charge density decreased, which resulted in the micelles＇ growth continuously. When the system pH was lowered to 8.64, flocculation occurred due to the attractive interactions among adjacent micelles. However, with the system pH increased up to 9.40, the micellar structures were also destroyed due to counterions Et3 NH＋ desorbing from the surface of the wormlike micelles.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2014年第8期969-973,共5页
Fine Chemicals
基金
国家自然科学基金(21366010)
海南省重点科技计划资助项目(ZDXM20120003)
海南大学服务地方经济社会发展项目(HDSF201305)~~
