A simple way of preparing large compound vesicles loaded with and without silver nanoparticles based on polystyrene-block-polyacrylonitrile

By a simple method, large compound vesicles (LCVs) and LCVs with silver nanoparticles (Ag@LCVs) are created from asymmetric polystyrene-block-polyacrylonitrile (PS-b-PAN) and silver precursor. The asymmetric PS-b-PAN is polymerized by sequential reverse atom transfer radical polymerization and atom transfer radical polymerization. Afterwards, by using N,N′-dimethylformamide as solvent and reductant for the silver precursor, LCVs and Ag@LCVs are produced through simple drop casting and evaporation of solution on the substrate. Transmission electron microscope images together with scanning electron microscopy images show that both LCVs and Ag@LCVs are flowerlike and of rough surfaces. Ultraviolet-visible spectrophotometer confirms the formation of Ag nanoparticles (Ag NPs). Specifically, the distribution of Ag NPs in Ag@LCVs is not uniform and they are principally in the center. Otherwise, adherence of simple vesicles and small hybrid nanoparticles of Ag NPs encapsulated within PS-b-PAN are observed. Finally, formation mechanisms for LCVs and Ag@LCVs are discussed.