Preparation of superparamagnetic γ-Fe2O3@LS@PS composite latex particles through pickering miniemulsion polymerization

Abstract

Based on the electrostatic interaction, prepared γ-Fe2O3 nanoparticles with high positive charges (+ 45 mv) were modified by negative charged ligninsulfonate (LS, - 34 mv) to synthensize LS/γ-Fe2O3 composite. LS is low-price, environmentally friendly and renewable biomacromolecule. The LS/γ-Fe2O3 composite were applied in a Pickering miniemulsion polymerization as the only stabilizer, without any auxiliary comonomers and surfactants. The surface anchored γ-Fe2O3 induced the formation of strawberry-like hybrid latex particles who were endowed with superparamagnetic functional properties. Furthermore, the effect of the ratios of LS to γ-Fe2O3 on the stability of the LS/γ-Fe2O3 composites was investigated. The content of γ-Fe2O3 in the LS/γ-Fe2O3 composites should be lower than 66.7 wt%, or the stability of the Pickering miniemulsion polymerization would be destroyed, owing to the charge neutralization behavior of the LS and γ-Fe2O3. Within this range, the latex particle size increased with the increasing of γ-Fe2O3 content.