Janus Micelle Formation Induced by Protonation/Deprotonation of Poly(2-vinylpyridine)-block-Poly(ethylene oxide) Diblock Copolymers

A novel approach to amphiphilic polymeric Janus micelles based on the protonation/deprotonation process of poly (2-vinylpyridine)-block-poly(ethylene oxide) (P2VP-b-PEO) diblock copolymers in THF is presented. It is found that addition of HCl to the micelles solution of P2VP-b-PEO copolymers leads to the formation of vesicles. Subsequently mixing a small amount of hydrazine monohydrate with the vesicle solution can induce the dissociation and reorganization of the vesicles into Janus micelles. When HCl is replaced by HAuCl(4) precursors, composite Janus particles containing gold in P2VP blocks are obtained.