Nanosizing of polymeric particles by suppressing growth via heterocoagulation using a 3D micro-network reactor

Abstract

Polymeric nanoparticles with diameters of ≤100 nm are employed in various fields owing to their unique properties. However, their environmental effects are concerning because of the large amounts of surfactants used during polymerization. Here, we fabricated nanoparticles without the use of surfactants via soap-free emulsion polymerization using melamine foam (MF), which is a thermosetting foam resin with a 3D micro-network structure, as a reactor. The particle size, which could be finely tuned by changing the porosity of the MF, correlated with the flow resistance of the MF. In addition, new particles were generated during seed polymerization within the MF, indicating that heterocoagulation was suppressed, which inhibited particle growth and yielded nanosized particles. This study provides a novel, green method of synthesizing polymeric nanoparticles, which are widely used in medical fields, without surfactants.