Attractive interaction between polydisperse brush-grafted nanoparticles due to autophobic dewetting effect

Abstract

In this research, we theoretically study the interparticle interactions between polymergrafted nanoparticles (NPs) within chemically identical homopolymer matrices. Using self-consistent field theory (SCFT) adopting finite volume method and multicoordinate-system scheme, we calculate interparticle interaction between two particles depending on several parameters such as the brush thickness, particle radius, molecular weight ratio of free to grafted polymers (α), brush chain polydispersity, and chain end mobility. Our results reveal that attractive interaction between NPs is induced by the surface tension resulting from autophobic dewetting of free homopolymers on brushes, which is promoted by increasing α. We also find that highly polydisperse brushes significantly suppress and nullify the autophobic dewetting at small α values, but the effect is limited in that finite attraction still remains at large α values.