Electromechanical response of lamellar forming ionic diblock copolymer thin films

Highlights: • Electromechanical responses of ionic diblock copolymers are investigated. • Electric permittivity of polar monomer is described using dipole moment. • Ion pair dissociation, counterion transport, and stress evolution are captured. Electromechanical responses of lamellar forming neutral-charged diblock copolymers (BCPs) in thin films are investigated using coarse-grained molecular dynamics simulations, where the electric permittivity of polymer monomer is described by explicitly introducing freely rotating dipoles. Effects of an applied electric field on the ion transport, morphological change and stress build-up are studied in detail. In particular, we focus on the responses to strong electric fields in terms of the ion dissociation and stress distribution along the film thickness. The different stages of BCP evolution under the electric field are characterized. This work paves a way towards establishing a modeling scheme that describes the response of ionic polymers in the presence of applied electric field.