title: PH-regulated molecular self-assemblies in a cationic-anionic surfactant system: from a "1-2" surfactant pair to a "1-1" surfactant pair.
abstract: 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.
authors.affiliation: 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.
authors.forename: Yiyang
authors.initials: Y
authors.lastname: Lin
authors.forename: Xue
authors.initials: X
authors.lastname: Han
authors.forename: Xinhao
authors.initials: X
authors.lastname: Cheng
authors.forename: Jianbin
authors.initials: J
authors.lastname: Huang
authors.forename: Dehai
authors.initials: D
authors.lastname: Liang
authors.forename: Cailan
authors.initials: C
authors.lastname: Yu