Brush-like block copolymer synthesized via RAFT polymerization for graphene oxide aqueous suspensions

Abstract

A brush-like block copolymer of poly(acrylic acid)-block-poly(oligo(ethylene glycol)methyl ether acrylate) (PAA-b-POEGA) was synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization, and its dispersing ability as polymeric dispersant for graphene oxide (GO) sheets in aqueous suspensions was studied in comparison with a traditional random copolymer having similar chemical units. The graphene oxide aqueous suspensions remained stable at a GO concentration as high as 100 g L⁻¹ for more than 7 days with the assistance of the prepared brush-like block copolymer, which could not be fulfilled by the random copolymer control group as dispersant. Measurements on polymer adsorption, zeta potential, shear viscosity, particle size analysis, and by small angle X-ray diffraction and scanning electron microscope were carried out to characterize the improved dispersing ability of the brush-like block copolymer for GO aqueous suspensions.