2004/03/31 by Jonathan V. Selinger, B. R. Ratna, Banahalli R. Ratna
Engineering · Physics and Astronomy · #Adhesion, Friction, and Surface Interactions #Advanced Materials and Mechanics #Advanced Sensor and Energy Harvesting Materials #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.70.041707
published as Phys. Rev. E 70, 041707 (2004) · 9 pages, including 5 postscript figures, uses REVTeX 4
arxiv created 2004/08/05 · openalex publication_date 2004/10/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
When liquid-crystalline elastomers pass through the isotropic-nematic transition, the orientational order parameter and the elastic strain vary rapidly but smoothly, without the expected first-order discontinuity. This broadening of the phase transition is an important issue for applications of liquid-crystalline elastomers as actuators or artificial muscles. To understand this behavior, we develop a lattice model of liquid-crystalline elastomers, with local directors coupled to a global strain variable. In this model, we can consider either random-bond disorder (representing chemical heterogeneity) or random-field disorder (representing heterogeneous local stresses). Monte Carlo simulations show that both types of disorder cause the first-order isotropic-nematic transition to broaden into a smooth crossover, consistent with the experiments. For random-field disorder, the smooth crossover into an ordered state can be attributed to the long-range elastic interaction.