title: Electrooptical behavior of aqueous (hydroxypropyl)cellulose liquid crystals containing imidazolium salts.
abstract: A dynamic control of the cholesteric coloration and optical clarity of aqueous (hydroxypropyl)cellulose (HPC) lyotropics is attainable under a weak electric field by employing a fluctuating ionic additive as P and T(c) shifter (P, cholesteric pitch; T(c), cloud point). The present Article demonstrates some examples of time-evolving gradation in reflection color and transparency for HPC liquid crystals containing various N-alkyl-substituted methylimidazolium salts ([CnMim][X]); this was perceivable when each anisotropic solution was sealed in a layer form between parallel slide glasses spaced by a pair of carbon electrodes and then electrified with a direct circuit. The electrooptical phenomenon was interpreted as being primarily due to generation of a disproportional dislocation of cation (CnMim(+))/anion (X(-)) constituents. Even after the electric supply was ceased, an appreciable potential difference remained in the color-gradated samples. It is suggested that the salt-containing liquid-crystalline system behaves like a quasi-capacitor as a viscous electrolytic medium of high resistance.
authors.affiliation: Division of Forest and Biomaterials Science, Graduate School of Agriculture,  Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Ito
authors.forename: Yoshikuni
authors.initials: Y
authors.lastname: Teramoto
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nishio
mesh_terms: D016880:Anisotropy; D002244:Carbon / Q000737:chemistry; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D003116:Color; D004566:Electrodes; D004574:Electromagnetic Fields; D007093:Imidazoles / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D055620:Optical Phenomena; D012492:Salts; D012996:Solutions; D014867:Water
chemical_list: D007093:Imidazoles; D012492:Salts; D012996:Solutions; D014867:Water; D002244:Carbon; D002482:Cellulose; C008079:hydroxypropylcellulose