Preparation of Particle Mixtures with Controlled Assembly Structures

Abstract

This study focused on utilizing two types of hydrogel particles (microgels) with distinct surface properties to precisely control interparticle interactions in aqueous environments and construct unique particle assemblies. The effects of electrostatic attraction and steric repulsion on the structural formation of assemblies were investigated in detail by systematically varying particle and salt concentrations. The findings revealed that raspberry-like aggregates formed at low salt concentrations, while medium salt concentrations maintained a uniform dispersion state, and high salt concentrations led to random aggregation. Furthermore, it became possible to directly observe swollen structures using fluorescence microscopy by utilizing fluorescently labeled microgels. This approach enhances the simplicity and efficiency of structural analysis for real-time observations of particle dynamics and assembly behavior. The results provide critical insights into controlling interparticle interactions and offer a foundational methodology for designing functional materials and achieving precise structural control at the nanoscale, with potential applications in material science and biological fields.