Cumulative steady state Monte Carlo method for processes with exchange between reactive species. Case of controlled radical copolymerization

A new, effective, kinetic Monte Carlo method for modeling processes with dynamic interconversion of two types of reactive species, especially systems of controlled radical (co)polymerization (CRP), is devised. Similarly as developed earlier cumulative hybrid Monte Carlo method (CHMC) it is based on virtual integration of less reactive, e.g. dormant in CRP, and most of more reactive (radicals in CRP) species into one category. Unlike CHMC method it is based on the quasi steady state approximation enabling increase of the simulation effectiveness. When the rate of activation/deactivation interconversions is high, then the simulation time is hundreds of times shorter than is required with the standard Gillespie method without losing the accuracy of the results. This is documented by modeling two exemplary CRP systems: one without depropagation reactions, modelable by using CHMC method, and the second with depropagation reactions, which could not be modeled with that method.