8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Fri 911:10-14:00P3.1Calculation of surface elastic constants of a Gay- Bernenematic liquid crystals with prolate molecules from newdirect correlation and pair distribution functionsAbolghasem Avazpour, 1 Mehrnosh Hashemi, 1 Ladan Avazpour, 2 and ForooghLotfi 31 Yasouj University, Yasouj, Iran, 7591961779, Yasouj, Iran2 College of Science, Yasouj branch, Islamic Azad University, Yasouj, Iran3 Faculty of Health Sciences, Yasouj University of Medical Sciences, Yasouj, IranAbstract In our earlier work [Phys. Rev. E, 82, 041701 (2010)] the bulk elastic constants werecalculated using Poniewierski-Stecki expressions and the new direct correlation function. Wecalculate the surface elastic constants, K13, K24 of Gay-Berne nematic liquid crystals atconstant temperature and density using the expressions proposed by Stelzer and co-workers[J. Chem. Phys. 103, 3098 (1995)]. The angular coefficients of the direct correlation function,which enter the final equations, have been determined using the new direct correlation and pairdistribution functions. By study of the model over a wide range of temperatures and densities formolecular elongation, K12 = 3, the detailed information is provided on the surface elastic behaviorof the Gay-Berne nematic. It is found that the results for the surface elastic constants are qualitativelydifferent from bulk elastic constants and are in agreement with the simulation results. Also,the values of the surface elastic constants, K13, are negative and magnitude of K13 and K24 aresmaller than the bulk elasticity. Keywords : surface elastic constants; Gay- Berne nematic; Newdirect correlation function; Stelzer expressions.1