Synthesis and aggregation behavior of amphiphilic nanostructures composed of carbosilane dendrimer with peripheral poly(ethylene glycol) moieties

Key Words:carbosilane dendrimer; aggregation; self-assembling; encapsulation

Abstract:Dendritic amphiphiles as novel building blocks are very important for self-assembling in the supramolecular chemistry area. In this work, a carbosilane dendrimer with hexamethylene as the branching unit (G1) was first synthesized as a hydrophobic core and then linked with poly(ethylene glycol) (PEG) units as the periphery by a hydrosilylation reaction to prepare an amphiphilic dendrimer (G1-PEG) with a yield of 27%. The aggregation behavior of G1-PEG in water was studied with surface tension, dynamic light scattering and transmission electron microscopy methods. The surface tension data showed that the critical aggregation concentration of such dendrimers in water is approximately 0.75 g L-1. The results of dynamic light scattering and transmission electron microscopy indicated that the aggregate size of G1-PEG dendrimers in water is related to the concentration. Small micelles of about 10 nm were found at high concentration, large vesicles of about 100 nm were observed at low concentration, and a mixture of micelles and vesicles was found at middle concentrations. The encapsulation of G1-PEG to a fluorescence probe verified the existence of a hydrophobic microenvironment in the aggregates at high concentrations of the amphiphilic dendrimer. (c) 2014 Society of Chemical Industry

Volume:63

Issue:10

Translation or Not:no