Superbasin strategy aided Monte Carlo simulation for modelling and accelerating dynamic process of photoiniferter-RAFT polymerization at microscopic scale

Abstract

Photo-iniferter reversible addition-fragmentation chain-transfer (PI-RAFT) polymerization provides precise control over polymer chain architecture under light irradiation. However, accurately modelling its dynamic processes, especially for the systems with dual chain transfer agents (CTAs), poses significant challenges. This study highlights two contributions in the development of a modelling approach and the exploration of kinetic insights into PI-RAFT. From a mathematical modelling perspective, a Superbasin-aided kinetic Monte Carlo (SA-kMC) model is developed, which accelerates simulations for dynamic PI-RAFT polymerization processes by orders of magnitude while preserving accuracy in capturing both microscopic and macroscopic system kinetics. The reliability and efficiency of the SA-kMC model are validated against standard kMC and the deterministic models. From a polymerization mechanistic standpoint, the SA-kMC model presents a methodological advancement for exploring the kinetics of PI-RAFT polymerizations using dual CTAs. Microscopic-scale simulations reveal that the inclusion of a fast CTA allows to attain the desired polymer properties much faster at the cost of a broader molecular weight distribution. The gained accuracy and speedup from this work enable the potential for further online control and process optimization in controlled radical polymerization processes.