Abstract
The critical exponents of the reentrant isotropic (I RE)–calamitic nematic (N C) and the N C–isotropic (I) phase transitions found in a lyotropic mixture of potassium laurate, decanol, and water are experimentally determined. Using optical birefringence measurements, along the entire range of the nematic phase, it was found that while the usual high temperature N C–I phase transition presents the well-known discontinuity, typical of a first order phase transition, with a critical exponent in the same class of universality of the three-dimensional Ising model, within the interval ( 0.36 ± 0.05 ), the low temperature N C–I RE phase transition presents strong indications of a second order phase transition, with a critical exponent in the interval ( 0.16 ± 0.01 ). This experimental achievement indicates that the high temperature and the low temperature (reentrant) nematic–isotropic phase transitions do not belongs to the same universal class.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call