Facile fabrication of triple-scale colloidal particles and its application in Pickering emulsions

Herein, we demonstrate a facile and scalable approach to prepare triple-scale colloidal particles via a one-step dispersion polymerization of glycidyl methacrylate and ethylene glycol dimethacrylate in a toluene/ethanol solvent mixture. The morphologies of the colloidal particles can be readily tuned by adjusting the composition of the binary solvent mixture and other copolymerization parameters. Based on the morphological evolution and size variations of the colloidal particles collected during the one-step dispersion polymerization process, a plausible formation mechanism was proposed for these triple-scale colloidal particles. The addition of toluene not only prolonged the nucleation time by increasing the solvency of the solvent mixtures, but also increased the swelling capability of the growing particles for the glycidyl methacrylate and ethylene glycol dimethacrylate. The formation of triple-scale structure was attributed to the elastic stress of the crosslinked polymer network, which extrudes the swellen monomer and crosslinker. In addition, colloidal particle with various surface roughness were utilized to stabilize Pickering emulsions, and the correlation between particle surface roughness and the properties of Pickering emulsion was also investigated. As the particle surface roughness increase, stable O/W Pickering emulsions with diameters of hundreds of microns were obtained.