Density dependence in the Landau-de Gennes theory for the nematic-isotropic phase transition

In this paper is presented an extension of the density dependence in the La ndau-de Gennes theory for the nematic to isotropic phase transition, taking into account this dependence for three phenomenological coefficients in th e free energy expansion. In this manner, a better agreement between the cal culated thermodynamic quantities and their experimental values was obtained near the nematic-isotropic phase transition. More. the theory leads to a b etter description of the temperature dependence of the order parameter in t he same temperature range.