title: Tricritical point induced by smectic ordering of a nematic gel.
abstract: The authors study volume phase transitions of a nematic gel immersed in a liquid crystal (LC) solvent, which shows a second-order nematic-smectic A phase transition (NST). Combining Flory's elastic energy [Principles of Polymer Chemistry (Cornell University Press, Ithaca, 1953)] for a swelling of the gel with the McMillan model [Phys. Rev. A 4, 1238 (1971)] for smectic ordering, the authors calculate the equilibrium swelling of the gel and smectic order parameters as a function of temperature. The authors take into account an attractive interaction parameter c between the gel and LC solvents. On increasing the value of the coupling constant c, a second-order NST of the gel is changed to a first-order one and a continuous volume phase transition of the gel is changed to a discontinuous one. The authors find a tricritical point of the gel induced by smectic ordering.
authors.affiliation: Department of Bioscience and Bioinformatics, Faculty of Computer Science and System Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka, Fukuoka 820-8502, Japan.
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Kushibe
authors.forename: Akihiko
authors.initials: A
authors.lastname: Matsuyama
mesh_terms: D002627:Chemistry, Physical / Q000379:methods*; D005782:Gels; D007202:Indicators and Reagents / Q000737:chemistry; D050866:Liquid Crystals; D015233:Models, Statistical; D008962:Models, Theoretical; D008970:Molecular Weight; D012997:Solvents; D013696:Temperature; D013816:Thermodynamics
chemical_list: D005782:Gels; D007202:Indicators and Reagents; D012997:Solvents