화학공학소재연구정보센터
Langmuir, Vol.22, No.5, 2045-2049, 2006
Transitions of organized assemblies in mixed systems of cationic bolaamphiphile and anionic conventional surfactants
The transition from vesicles to tubelike structures has been studied in mixed systems of cationic bolaamphiphile BPHTAB [biphenyl-4,4'-bis(oxyhexamethylenetrimetliylammonium bromide)] and its oppositely charged conventional surfactants with transmission electron microscopy (TEM) and dynamic light scattering (DLS). This transition can be attributed to the fact that tubelike structures are more stable aggregates than vesicles because of the special molecular packing in the aggregates of the mixed systems. The effects of temperature and salt addition on this transition have also been investigated, and the rate of the transition was found to be strongly dependent on temperature. Addition of the appropriate amount of NaBr will accelerate the transition from vesicles to tubelike structures. but the vesicles will transform into micelles at higher salt concentration. Moreover, the micelle-vesicle transition can be realized by addition of n-octanol in the mixed system of BPHTAB/sodium caprate (SC) at higher salt concentrations.