Interaction of different sized quantum dots with surfactant assemblies

Abstract

The present work shows the formation of vesicles by simply incubation of mercaptosuccinic acid (MSA) capped CdTe-Quantum dots and cationic hexadecltrimethylammonium bromide (CTAB) surfactant. Aggregation and self-assemble behavior in an aqueous solution of the mixture of cationic surfactant CTAB and anionic MSA capped CdTe-QDs have been studied by UV-vis spectrophotometer, photoluminescence (PL) spectroscopy, field-emission scanning electron microscope (FE-SEM), confocal microscope and PL microscopy. Initial aggregation and subsequent formation of vesicles occurs at high concentration of surfactant which has been observed for both smaller and bigger size MSA-capped CdTe QDs. No such effects have been observed for anionic sodium dodecyl sulfate (SDS) and neutral Triton X-100 (TX-100) surfactants. The results indicate the involvement of specific electrostatic interaction between the carboxyl groups of MSA and positively charged quaternary ammonium head groups CTAB.