Slow stress relaxation in randomly disordered nematic elastomers and gels
arXiv:cond-mat/9805382 · doi:10.1103/PhysRevLett.81.4436
Abstract
Randomly disordered (polydomain) liquid crystalline elastomers align under stress. We study the dynamics of stress relaxation before, during and after the Polydomain-Monodomain transition. The results for different materials show the universal ultra-slow logarithmic behaviour, especially pronounced in the region of the transition. The data is approximated very well by an equation Sigma(t) ~ Sigma_{eq} + A/(1+ Alpha Log[t]). We propose a theoretical model based on the concept of cooperative mechanical resistance for the re-orientation of each domain, attempting to follow the soft-deformation pathway. The exact model solution can be approximated by compact analytical expressions valid at short and at long times of relaxation, with two model parameters determined from the data.
4 pages (two-column), 5 EPS figures (included via epsfig)
Cited by in corpus (7)
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- Soft and non-soft structural transitions in disordered nematic networks
- Modeling elastic instabilities in nematic elastomers
- Instabilities in liquid crystal elastomers
- A macroscopic constitutive relation for isotropic-genesis, polydomain liquid crystal elastomers
- Elastic Effects in Disordered Nematic Networks
- Deformation localisation in stretched liquid crystal elastomers