Portal de Periódicos da CAPES

Bistable Electro-optical Fast Switching for Induced Smectic (Liquid Crystalline Polymer/Liquid Crystals) and (Pseudo Liquid Crystalline Copolymer/Liquid Crystals) Composite Systems

1997; American Chemical Society; Volume: 30; Issue: 11 Linguagem: Inglês

10.1021/ma961754u

1520-5835

Hirokazu Yamane, Hirotsugu Kikuchi, Tisato Kajiyama,

Photonic and Optical Devices

Reversible and bistable electro-optical switching characteristics of induced smectic composite systems composed of a side chain nematic liquid crystalline polymer (nematic LCP) and its copolymer with weak polar methoxy terminal groups in the side chains and low molecular weight nematic liquid crystals (nematic LCs) with each strong polar cyano end have been investigated. The liquid crystalline copolymer (LCcoP) with weak polar methoxy terminal groups in the side chains was used to improve the response speed at room temperature for the bistable and reversible light switching of the binary composite system. Since LCcoP with 52.5 mol % substituted mesogenic side chains did not exhibit mesophase characteristics, this LCcoP was named as pseudo LCcoP in the present study. The (pseudo LCcoP/nematic LCs) composite system showed an induced smectic phase over a wide range of mixing concentration and temperature. A reversible and bistable electro-optical switching with a short response time (∼100 ms) was realized for the induced smectic binary composite system upon the application of an appropriate electric field at room temperature. Also, the binary composite system showed a reversible and bistable electro-optical switching based on the sign reversal of the dielectric anisotropy upon the application of ac electric fields with high (∼kHz) and higher (∼100 kHz) driving frequencies.