Relation between Structural Disruption and Memory Effects in Side-Chain Liquid Crystal Elastomers

Side-chain liquid crystal elastomers (SCLCEs) are intrinsically anisotropic materials that combine the properties of elastomers with the stimulus-responsiveness of liquid crystals, resulting in synergistic properties. In particular, SCLCEs consist of slightly crosslinked polymeric networks where liquid crystal (LC) moieties are attached to polymeric backbones as pendant side groups, either in an end-on or side-on manner.

Using molecular dynamics, we study the impact of two types of LC moieties in various compositions and sequences on the thermal response and deformation behavior of SCLCEs. We build upon our recently developed coarse-grained model for the conformational molecules of SCLCE networks [ACS Nano 17, 24790-24801 (2023)]. This model agrees with experimentally observed mesophases and qualitatively reproduces the non-monotonic thermal trend caused by structural disruption due to LC composition-a factor that also affects relaxation dynamics.

The crosslinking degree of the polymeric network adds another layer of complexity, as memory effects manifest in varying mesophases induced in different thermodynamic states. LC composition and sequence further expand the potential for designing complex SCLCE deformation responses beyond those of single LC-type systems.