Nanogel degradation promotes interfacial spreading

Microgels and nanogels are being used extensively in applications ranging from drug delivery to soft emulsifiers. In many of these applications, degradation of the polymer network plays an important role. We model first order degradation kinetics in nanogels using our recently developed Dissipative Particle Dynamics (DPD) based approach. We first simulate equilibration of nanogels in a surrounding liquid phase. The equilibrated nanogels attain an equilibrium swelling polymer volume fraction and radius of gyration. We then place nanogels in a vicinity of a liquid-liquid interface and characterize adsorption of nanogels onto the interface. We characterize spreading of nanogels onto the interface by measuring properties such as shape anisotropy and extent of spreading of the nanogel particle. The extent of spreading over the interface is governed by a competition between the nanogel’s inherent elasticity and the interfacial energy. Introducing stimul-controlled degradation in the adsorbed nanogels causes an enhancement in spreading behavior. We further compare the degradation behavior at the interface to degradation of the nanogels suspended in the liquid phase.