Transitions of Organized Assemblies in Mixed Systems of Cationic Bolaamphiphile and Anionic Conventional Surfactants

Abstract

The transition from vesicles to tubelike structures has been studied in mixed systems of cationic bolaamphiphile BPHTAB [biphenyl-4,4'-bis(oxyhexamethylenetrimethylammonium 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 tube-like 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 tube-like 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.

Some Properties of Sodium Dodecyl Sulfate Functionalized Multiwalled Carbon Nanotubes Electrode and Its Application on Detection of Dopamine in the Presence of Ascorbic Acid

“…Under these assumptions, d of the SDS membrane is estimated as 1.23 nm. And it is reported that the distance from the polar head to the tail end of alkyl chains for SDS monolayer is 1.7 nm [41]. The estimated value of d suggests that, when MWNTs electrode is soaked in SDS solution, SDS molecules can form a monolayer on the surface of MWNTs slantways.…”

Lipid-Based Nanoparticles as Pharmaceutical Drug Carriers: From Concepts to Clinic

“…This is based on the observation that bolaamphiphiles are known to form self-aggregating structures that readily convert from vesicles to fibers or sheets upon small changes in their structure,128,151 especially with small vesicles due to curvature considerations 186. Thus, vesicles made from bolaamphiphiles will have superior stability as described above, and yet, upon removal of the head groups, the content of the vesicles will be readily released.…”

Recent advances in the mixed systems of bolaamphiphiles and oppositely charged conventional surfactants

“…Under this background, researches on the mixed systems of bolas and oppositely charged conventional surfactant systems have attracted increasing attentions [64][65][66][67][68][69][70][71][72][73]. Many interesting novel results have been reported.…”