Kinetics and morphologies in polymerization-induced cooperative assembly: a computer simulation investigation

In the last decade, polymerization-induced self-assembly (PISA) has emerged to be a quite popular technique for preparing a variety of nanoassembly structures in a selective solvent. As a special technique of PISA, polymerization-induced cooperative assembly (PICA) is believed to be able to produce more variable nanostructures and its ways of regulation seem more flexible. The process of PICA is studied systematically with a simulation method for discovering possible ways of regulation of morphologies. We find that the existence of solvophobic homopolymers yields a 'chain growth retarding effect', which effectively slows down the reaction kinetics of the polymerization. Besides proving the transition from lower-order morphologies to higher-order morphologies as reported in experiments, we also find a novel transition from higher-order morphologies to lower-order morphologies, as a result of the self-adaptation behavior of the system. For the first time, we demonstrate that this behavior is able to be well described as a kind of inverse flip-flop process of vesicle structures to thermodynamically stable micelle structures. We also find that the obvious contrast of length between the solvophilic macro-chain transfer agents and solvophobic blocks is beneficial to the emergence of plentiful kinds of structures. The results of this study are helpful for understanding the crucial factors for precisely regulating the morphologies in PICA, as well as guiding the way to improve experimental technologies. (c) 2021 Society of Industrial Chemistry.