title: Liquid crystal physical gel formed by cholesteryl stearate for light scattering display material.
abstract: A liquid crystal physical gel was prepared by the self-assembly of cholesteryl stearate in a nematic liquid crystal, 4-cyano-4'-pentylbiphenyl. The electro-optical properties were tuned by varying the gelator concentration and the gelation conditions. Polarized optical microscopy revealed that cholesteric cholesteryl stearate induced chiral nematic phase in 4-cyano-4'-pentylbiphenyl during the gelation process. As a result, a plate-like gel structure consisting of spherical micropores was formed, as observed by scanning electron microscopy. Electron spin resonance spectroscopy showed that the liquid crystal director orientations in these macrophase-separated structures were massively randomised. For these reasons, the liquid crystal physical gel generated a strong light scattering effect. For 48.0wt% cholesteryl stearate gelled 4-cyano-4'-pentylbiphenyl, the turbid appearance could be switched to a transparent state using a 5.0V alternating current. The response time was about 3.7μs. This liquid crystal physical gel has potential for use in light scattering electro-optical displays.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
authors.forename: W L
authors.initials: WL
authors.lastname: Leaw
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia. Electronic address: che@kimia.fs.utm.my.
authors.forename: C R
authors.initials: CR
authors.lastname: Mamat
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
authors.forename: S
authors.initials: S
authors.lastname: Triwahyono
authors.affiliation: Department of Chemical Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia; Centre of Hydrogen Energy, Institute of Future Energy, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
authors.forename: A A
authors.initials: AA
authors.lastname: Jalil
authors.affiliation: Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
authors.forename: N
authors.initials: N
authors.lastname: Bidin
keywords: 5CB; Cholesteryl stearate; Light scattering; Liquid crystal physical gel