UV-Manipulation of Order and Macroscopic Shape in Nematic Elastomers
Abstract
A range of monodomain nematic liquid crystal elastomers containing differing proportions of photo-isomerisable mesogenic moieties, which turn from a rod-like to a kinked shape upon ultraviolet (UV) irradiation, was studied. Depending on the proportion and positional role of the photo-sensitive groups in the crosslinked polymer network, different types and magnitudes of response were found. The principle consequence of such photo-isomerisation is the destabilisation of the nematic phase, whose order parameter depends on temperature in a near-critical fashion. Accordingly, the effect of UV-irradiation is dramatically enhanced near the critical temperature, with the associated reduction in the nematic order parameter manifesting as a change in the macroscopic shape of the elastomer samples, producing a large uniaxial contraction. Theoretical analysis of this phenomenon gives a good quantitative agreement with experiment.
Cite
@article{arxiv.cond-mat/0111430,
title = {UV-Manipulation of Order and Macroscopic Shape in Nematic Elastomers},
author = {P. M. Hogan and A. R. Tajbakhsh and E. M. Terentjev},
journal= {arXiv preprint arXiv:cond-mat/0111430},
year = {2007}
}
Comments
10 pages, 11 EPS figures; Revtex 4