Revealing the Aggregation Mechanism, Structure, and Internal Dynamics of Poly(vinyl alcohol) Microgel Prepared through Liquid–Liquid Phase Separation

The use of technologies based on soft polymer particles represents an effective way to deliver target molecules with a specific function. To design a well-performing delivery system, it is fundamental to rationalize both the aggregation and the structural properties of such particles. In this study, we present the kinetic and structural characterization over time of poly(vinyl alcohol) (PVA) microgels obtained through a salting-out process in the presence of NaCl. We have analyzed how both the polymer and salt concentrations affect the aggregation process. The aggregation rate as well as the morphology and physico-chemical parameters, such as mass and chain density of the microgels, have been determined through static and dynamic light scattering and discussed in the framework of the diffusion-limited and reaction-limited colloid aggregation. Insights into the polymer chain arrangements and their dynamics have been gained by means of small-angle neutron scattering and neutron spin-echo measurements. As a ...