title: Criticality controlled by cross-linking density in liquid single-crystal elastomers.
abstract: A high-resolution calorimetry and deuteron-nuclear magnetic resonance study of a paranematic-nematic phase transition was performed on liquid single-crystal elastomers. We show that density variations of both rodlike and pointlike cross-links strongly affect the mean value and the dispersion of local mechanical fields. The system exhibits an inherent weakly disordered orientational state composed of regions with the temperature profile of the nematic order parameter ranging from first order to supercritical. On increasing the cross-linking density the predominantly first order thermodynamic response transforms into a predominantly supercritical one.
authors.affiliation: Jozef Stefan Institute, 1001, Ljubljana, Slovenia.
authors.forename: George
authors.initials: G
authors.lastname: Cordoyiannis
authors.forename: Andrija
authors.initials: A
authors.lastname: Lebar
authors.forename: Bostjan
authors.initials: B
authors.lastname: Zalar
authors.forename: Slobodan
authors.initials: S
authors.lastname: Zumer
authors.forename: Heino
authors.initials: H
authors.lastname: Finkelmann
authors.forename: Zdravko
authors.initials: Z
authors.lastname: Kutnjak