Non-Equilibrium Dynamics Simulations of Vesicles and Micelles by Self-Assembly of Block Copolymers with Double Thermoresponsivity


Yu-Hang Tang


Yu-Hang Tang, Zhen Li, Xuejin Li, Mingge Deng, George Karniadakis

Author Affiliation: 

Brown University


We present an energy-_conserving Dissipative Particle Dynamics (DPD) simulation study on the self assembly behavior of thermo_responsive polymers (TRPs). By treating the internal energy of solvent and polymers as a degree of freedom of the coarse_-grained particles, we were able to model the assembly process of TRPs in systems with non_trivial time-_evolution of temperature distribution. First, we found that both external and intrinsic factors can affect the final assembly morphology via altering the assembly pathway of thermoresponsive micelles. Second, a frequency regime was identified, where thermoresponsive unilamellar vesicles can sustain repeated heating_-cooling cycles, while the collapse probability and half_life of the vesicles under frequencies that cause vesicle destruction were also quantified. Third, we found that two molecular movement modes dominate in thermoresponsive bilayer membranes during the inversion of composition. Last, we demonstrated that doubly thermoresponsive micelles and vesicles present unique hydrodynamic behavior when flowing through capillaries with non-_uniform temperature distribution.