Mesoscopic study of micellar inversion pathways of the thermoresponsive PMEMA–PSBMA copolymer via applied stimulus intensity

Abstract

In this work, two micellar inversion pathways of a thermoresponsive material were explored through dissipative particle dynamics simulations. The simulation results have demonstrated that poly(2-(N-morpholino)ethyl methacrylate)–poly(sulfobetaine methacrylate) (PMEMA–PSBMA) copolymer has tuneable critical solution temperatures (LCST and UCST) and can develop two different micellar states with a well-defined core–corona structure. All transitory and metastable stages on each micellar inversion pathway are controlled by the combination of the critical solution temperatures of each polymeric segment and by the applied stimulus intensity. The first structural inversion pathway (continuous thermal heating) involves three transitory stages (micellar dissociation, stabilization of free unimer chains and formation of inverse micelles), and the second micellar inversion pathway (abrupt thermal heating) implies two simultaneous transitory stages (immersion and ascent of polymeric segments). Each structural inversion pathway is described and analysed in detail in this document.