Polymer-Fe₃O₄ Composite Janus Nanoparticles

Abstract

A Fe3O4 nanoparticle (NP) based on composite Janus NP with single polymer chain is prepared by termination of the modified Fe3O4 NP with the anionic living polymer chain. The requisite that the polymer chain should be sufficiently large over the NP diameter determines the grafting of single polymer chain. From the opposite side of the NP surface, functional species can be selectively grown for example grafting responsive PNIPAM by ATRP. Besides simple combination of the thermal and magnetic responsive performances of different components, the PS–Fe3O4–PNIPAM composite Janus NP shows additional interactive performance such as NIR-triggered Janus/hydrophobic transition at low surrounding temperature below LCST ∼ 32 °C.