title: Nanoparticle induced director distortion and disorder in liquid crystal-nanoparticle dispersions.
abstract: Colloidal dispersions of nanoparticles in liquid crystals have been investigated experimentally using a model system consisting of the thermotropic liquid crystalline compound 4-n-octyloxy-4'-cyanobiphenyl (8OCB) doped with BaTiO(3) nanoparticles. We show that the physical properties of these dispersions can vary considerably depending on the method of preparation of the dispersions. We also find that aging the sample can improve dispersal of the nanoparticles in the host liquid crystal. Decreases in the isotropic to nematic transition temperature, parallel component of the dielectric constant and orientational order parameter are observed for the dispersions compared to the behaviour of pure 8OCB. These decreases have been explained in terms of orientational disorder and defects induced by the nanoparticles.
authors.affiliation: Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560 080, India.
authors.forename: Meenal
authors.initials: M
authors.lastname: Gupta
authors.forename: Ipsita
authors.initials: I
authors.lastname: Satpathy
authors.forename: Arun
authors.initials: A
authors.lastname: Roy
authors.forename: R
authors.initials: R
authors.lastname: Pratibha
mesh_terms: D017609:Barium Compounds / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D050866:Liquid Crystals / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: C495061:4'-octyl-4-cyanobiphenyl; D017609:Barium Compounds; D001713:Biphenyl Compounds; D003102:Colloids; D009570:Nitriles; C024547:barium titanate(IV); D014025:Titanium