Vesicles Formation Induced by Layered Double Hydroxides in Mixture of Lauryl Sulfonate Betaine and Sodium Dodecyl Benzenesulfonate

摘要

This paper reports that structurally positively charged layered double hydroxides (LDHs) nanoparticles induce the vesicle formation in a mixture of a zwitterionic surfactant,lauryl sulfonate betaine (LSB),and an anionic surfactant,sodium dodecyl benzenesulfonate (SDBS). The existence of vesicles was demonstrated by negative-staining (NS-TEM) and freeze-fracture (FF-TEM) transmission electron microscopy and confocal laser scanning microscopy (CLSM). The size of vesicles increased with the increase of volume ratio (Q) of MgAl-LDHs sol to the SDBS/LSB solution. A new composite of LDHs nanoparticles encapsulated in vesicles was formed. A possible mechanism of LDHs-induced vesicle formation was suggested. The positive charged LDHs surface attracted negatively charged micelles or free amphiphilic molecules,which facilitated their aggregation into a bilayer membrane.The bilayer membranes could be closed to form vesicles that have LDHs particles encapsulated. It was also found that an adsorbed compound layer of LSB and SDBS micelles or molecules on the LDHs surface played a key role in the vesicle formation.