Taeko Urano

Denatured tris(quinolin-8-olato)aluminium: a new material for organic electroluminescent cells

Tris(quinolin-8-olato)aluminium (Alq3) was denatured by a heating process. The denaturation was followed with infrared spectroscopy, differential thermal analysis and elemental analysis. The denatured Alq3 showed electroluminescent (EL) characteristics no weaker than normal Alq3.

Dynamics of a nematic liquid crystal on a PBLG-CRA film. Time-resolved infrared spectroscopic study

Abstract The time response of a nematic liquid crystal (LC) to an applied electric field is proposed as a new dynamic index for the interaction between LCs and LC-orienting films. For a PBLG-CRA (chemical reaction alignment) film, the unique LC response observed by time-resolved infrared spectroscopy suggested a time-dependent LC-orienting effect induced by the film. On the basis of the electric field polarity dependence of the LC dynamics, we describe a model in which the applied electric field influences the orienting effect of the film, the latter originating from the inherent dipole moment of the film.

Dynamic Behavior of a Hydrogen-Bonded Liquid Crystal Induced by the Orienting Film with a Large Dipole Moment

Abstract Poly-(γ-benzyl-L-glutamate) molecules have been bonded covalently to a flat substrate via carbonyl end group to form an aligned dipole layer (CRA film). The authors have evaluated the electric influence of the CRA film on the dynamic change of the hydrogen-bonded liquid crystalline complex of 4-hexyloxybenzoic acid and 4-nonylpyridine (6OBA-9Py) by means of time-resolved infrared spectroscopy. Using the CRA film as an orienting film for 6OBA-9Py, the absorbance change of the complex when burst electric field was applied had many steps in response to the change of its sign. Moreover, the movement of the 6OBA-9Py complex was induced by an external electric field, not only in the direction of the complex long axis but also in that of the complex short axis. This characteristic dynamic behavior of the 6OBA-9Py complex was due to the weak hydrogen bonding.

A new variable orienting force for liquid crystals which has its origin in the electric property of poly-γ-benzyl-L-glutamate CRA film

Liquid crystal (LC) quick response is achieved by switching the orienting force of poly-γ-benzyl-L-glutamate chemical reaction alignment (CRA) film in response to an electric field.