Modeling Polymerization-Induced Self-Stratifying Coatings

Multilayer coatings have various applications such as car paint, self-healing, and anti-fouling surfaces, where it is useful to have multiple layers with complementary functions. However, multilayer coatings involve many processing steps, increasing cost and the possibility of interfacial failures. Self-stratifying coatings are excellent candidates to address these issues, by relying on the assembly (i.e. stratification) of a singly-applied coating that minimizes cost while preventing interfacial failures. Our goal is to develop a computational model to understand the fundamental processes underlying the behavior of self-stratifying coatings, thereby predicting the physical forces driving stratification and facilitating the chemical design of new coatings. We present the simulation model developed to study phase separation in binary mixtures where components undergo a polymerization reaction, a relevant model system for understanding polymerization-induced self-stratification. We use a combination of field theoretic simulations and numerical evaluation of Cahn-Hilliard theory, along with models of reaction kinetic models, to understand the interplay of polymerization and phase separation dynamics in self-stratifying systems.