Effects of Drying Process on PEG-Silica Colloidal System Interactions

Abstract

In the colloids-polymer mixture system, microstructures of particles and polymers are strongly dependent upon their interactions, which can be systemically varied by the component concentrations. When the colloidal system is concentrated with solvent evaporation, the relative concentration of the components drives the continuous change of the interparticle interactions. In our study, we focus on the effects of the drying process on polymer and particle interactions by comparing the two cases. The first case is the “non-dried” sample made of concentrated silica nanoparticle (NP) solution where the desired concentration is met by dilution. The second case is the “dried” samples, which undergo the drying process to reach the desired particle concentration. The final particle volume fraction of each solution sample is the same as 0.12. The system is composed with silica NPs in water with poly(ethylene glycol) varying molecular weight. The microstructure was analyzed by SAXS experiment.