摘要
研究了温度对十六烷基三甲基溴化铵胶束盐溶液粘度的影响.发现随温度的上升溶液的粘度由于圆柱形长棒胶束解体为小的球形胶束而下降.从ΔG/T对1/T作图法求得的ΔH值较从Eyring粘度理论计算的ΔG值要大得多.胶束的棒球转变不是一步而是分多步实现的,在转变过程中大胶束处于一系列的“活化结构”状态.认为与温度有关的ΔG值是粘流过程中形成空穴的自由能变,而ΔH值为包含有大胶束解体为小胶束过程粘性流动的总活化能.
:The effect of temperature on the viscosities of cetyltrimethylammonium bromide(CTAB) in the presence of different added salt was investigated.It was found that the viscosities of CTAB micelle solutions decrease with increasing temperature due to the break up of the cylindrical rodlike micelles.The value of ΔH obtained from the plot of ΔG/T versus 1/T are much larger than the values of ΔG calculated from Eyring equation at various temperatures.It is proposed that the transition of rod to spherical micelles can not be conceivable in only one step but in infinite steps,and in each step the rodlike micelles are always in equilibrium with activated micelle aggregates which can rapidly translate into smaller cylindrical micelles,and finally into spherical micelles.ΔH consistently larger than ΔG is associated with a breakdown of cylinderical micelles into smaller spherical micelles since this transition also requires energy to weaken the intermolecular forces and to increase the area of interface.
出处
《江西师范大学学报(自然科学版)》
CAS
1997年第4期347-353,共7页
Journal of Jiangxi Normal University(Natural Science Edition)
基金
江西省自然科学基金
关键词
粘度
CTAB
胶束
盐溶液
表面活性剂
:cetyltrimethylammonium bromide,viscosity,rodsphere transition