Eur. Phys. J. E 5, 295-307
Mechanical and order rigidity of nematic elastomers
G.G. Pereira and M. WarnerCavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
(Received 29 September 2000)
Abstract
We calculate the ratio of moduli for extension parallel
and perpendicular to the director of nematic elastomers.
Elastomers in practice are not ideal nematics with a jump from a
finite to zero-order parameter with increasing temperature. Some
classes behave as if under effective external fields. These are
really internal in origin and leave the system subcritical (still
with jumps) or supercritical. We give expressions for general
non-ideality and memory of formation conditions, along with its
translation into values of the "fields". For the case of
supercritical fields, we find that the modulus ratio deviates more from
unity, in accord with experiment, than in the subcritical case.
61.30.-v - Liquid crystals.
82.70.-y - Disperse systems; complex fluids.
81.40.Jj - Elasticity and anelasticity, stress-strain relations..
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001