Lin Yiyang, Han Xue, Cheng Xinhao, Huang Jianbin, Liang Dehai, Yu Cailan
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Langmuir. 2008 Dec 16;24(24):13918-24. doi: 10.1021/la802593n.
With the aid of pH variation, direct transformation of a "1-1" cationic-anionic surfactant pair to a "1-2" cationic-anionic surfactant pair was attained in the system of cetyltrimethylammonium bromide and n-decylphosphoric acid. Owing to the transformation of a "1-1" pair to a "1-2" pair, diverse microstructures and peculiar phase behavior in this cationic-anionic surfactant mixture was obtained at different pH. It is proposed that pH can be manipulated for effectively tailoring the self-assembled organization in this cationic-anionic surfactant system, including spherical micelle, wormlike micelle, vesicle, and lamellar structure. In contrast to the conventional "1-1" surfactant pair, the "1-2" cationic-anionic surfactant pair exhibits unexpectedly weak aggregating ability. It is suggested that the hydrated volume of surfactant headgroup should be taken into consideration to better elucidate the self-assembly behavior of these "1-2" cationic-anionic surfactant mixtures.
在十六烷基三甲基溴化铵和正癸基磷酸体系中，借助pH值变化，实现了“1-1”阳离子-阴离子表面活性剂对向“1-2”阳离子-阴离子表面活性剂对的直接转变。由于“1-1”对向“1-2”对的转变，在不同pH值下，该阳离子-阴离子表面活性剂混合物获得了多样的微观结构和独特的相行为。研究表明，可通过调控pH值有效定制该阳离子-阴离子表面活性剂体系中的自组装结构，包括球形胶束、蠕虫状胶束、囊泡和层状结构。与传统的“1-1”表面活性剂对相比，“1-2”阳离子-阴离子表面活性剂对表现出出人意料的弱聚集能力。建议考虑表面活性剂头基的水合体积，以更好地阐明这些“1-2”阳离子-阴离子表面活性剂混合物的自组装行为。
