title: Surface free energies for nematic shells.
abstract: We propose a continuum model to describe the molecular alignment in thin nematic shells. By contrast with previous accounts, the two-dimensional free energy, aimed at describing the physics of thin films of nematics deposited on curved substrates, is not postulated, but it is deduced from the conventional three-dimensional theories of nematic liquid crystals. Both the director and the order-tensor theories are taken into account. The so-obtained surface energies exhibit extra terms compared to earlier models. These terms reflect the coupling of the shell extrinsic curvature with the nematic order parameters. As expected, the shape of the shell plays a key role in the equilibrium configurations of nematics coating it.
authors.affiliation: Dipartimento di Ingegneria dell'Innovazione, Università del Salento, via per Monteroni, Edificio "Corpo O," 73100 Lecce, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Napoli
authors.forename: Luigi
authors.initials: L
authors.lastname: Vergori
mesh_terms: D003198:Computer Simulation; D004735:Energy Transfer; D050866:Liquid Crystals / Q000737:chemistry*; D008567:Membranes, Artificial; D008956:Models, Chemical; D008958:Models, Molecular; D044367:Phase Transition; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial