title: Density functional theory of nematic elasticity: softening from the polar order.
abstract: Recent experiments have evidenced some unconventional features in the elasticity of nematics, which cannot be explained by standard microscopic theories. Here, in the framework of a second-virial density functional theory, we have developed a general approach, relaxing the usual assumption that the angular distribution of particles with respect to their local director is unaffected by the deformation. We show that, for particles with polar symmetry, a new contribution to the splay and bend deformation free energy arises, associated with the onset of polar order. Calculations for conical and bent-shaped particles reveal dramatic softening of the splay and the bend mode, respectively, which eventually may lead to spontaneous deformation.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, I-35131 Padova, Italy. alberta.ferrarini@unipd.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: De Gregorio
authors.forename: Elisa
authors.initials: E
authors.lastname: Frezza
authors.forename: Cristina
authors.initials: C
authors.lastname: Greco
authors.forename: Alberta
authors.initials: A
authors.lastname: Ferrarini