Non-Isothermal Model for Nematic Spherulite Growth

NASSER M. ABUKHDEIR; EZEQUIEL R. SOULÉ; ALEJANDRO D. REY

LANGMUIR

American Chemical Society

Año: 2008 vol. 24 p. 13605 - 13613

0743-7463

A computational study of the growth of two-dimensional nematic spherulites in an isotropic phase was performedusing a Landau-de Gennes-type quadrupolar tensor order parameter model for the first-order isotropic/nematic transitionof 5CB (pentylcyanobiphenyl). An energy balance, taking anisotropy into account, was derived and incorporated intothe time-dependent model. Growth laws were determined for two different spherulite morphologies of the form tn,with and without the inclusion of thermal effects. Results show that incorporation of the thermal energy balancecorrectly predicts the transition of the growth law exponent from the volume driven regime (n ) 1) to the thermallylimited regime (approaching n ) 1/2), agreeing well with experimental observations. An interfacial nematodynamicmodel is used to gain insight into the interactions that result in the progression of different spherulite growth regimes.