title: Nickel Oxide Nanoparticles Doped Liquid Crystal System for Superior Electro-Optical Properties.
abstract: We examined the properties of nematic liquid crystal (N-LC) systems with dispersed nickel oxide nanoparticles (NPs). Uniform LC alignments with regular pretilt angles were achieved on rubbed polymer surface regardless of NiO nanoparticles concentration. We confirmed the electro-optical characteristics of twisted nematic (TN) cells containing NiO nanoparticles on rubbed polymer surface, which exhibited lower threshold voltages and faster response times with less capacitance hysteresis than pure LC cells. It is clear that the response time of TN cells on rubbed polymer surfaces decreases with increasing the NiO nanoparticles concentration. These results demonstrate the relationship between NP doping concentration and trapping of impurity ions, and were confirmed by a software simulation of electric flux and field density. NiO nanoparticles in the LC cells focused the electric field flux and strengthened the electric field. Further, NiO nanoparticles in LC medium trapped charged ionic impurities and suppressed the screen effect, leading to a stronger electric field and the van der Waals interactions between LC molecules and the alignment layers.
authors.forename: Hak Moo
authors.initials: HM
authors.lastname: Lee
authors.forename: Hyung-Koo
authors.initials: HK
authors.lastname: Chung
authors.forename: Hong-Gyu
authors.initials: HG
authors.lastname: Park
authors.forename: Hae-Chang
authors.initials: HC
authors.lastname: Jeong
authors.forename: Jeong-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Tae-Kyu
authors.initials: TK
authors.lastname: Park
authors.forename: Dae-Shik
authors.initials: DS
authors.lastname: Seo
mesh_terms: D050866:Liquid Crystals / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D055095:Optics and Photonics
chemical_list: D009532:Nickel; C028007:nickel monoxide