Phase Separation of Polymer Blends Induced by an External Static Electric Field (Nov, 10.1007/s10118-022-2877-z, 2022)

The mechanism of the phase separation of polymer blends in the presence of a static electric field was investigated using the molecular dynamics with a modified coarse-grained polarizable model. Two electric field effects, i.e., the promotion and hindrance of the phase separation, were found in the system of the upper critical solution temperature (UCST) by varying the dielectric properties of polymer components. Our simulation directly demonstrated that the electric field effects originate from the energy changes of intramolecular unit polarization, intermolecular van der Waals (VDW) and Coulomb interactions induced by the external electric field. The relationship of the energy change and the dielectric constant for the system under electric field is obtained. The interface orientation under electric field was found to happen even before the transition point of phase separation. By assuming that the relative order parameter of the phase separation undergoes the same fluctuations for a system with and without an electric field, the transition temperature under an electric field can be predicted, and quantitative consistency with simulations is obtained. © 2023, Chinese Chemical Society Institute of Chemistry, Chinese Academy of Sciences.