Comparative study of acoustic relaxation time of cholesteric liquid crystal and mixtures

International Conference on Advances in Materials and Manufacturing Applications 2016

Bhave, Manisha G.^1 ; Gharde, Rita^2 ; Radha, S.^2

Siddharth College of Arts Science and Commerce, Fort, Mumbai

400001, India^1

Department of Physics, University of Mumbai, Santacruz (E), Mumbai

400098, India^2

关键词: Cholesteric-isotropic transition;    Comparative studies;    Electro-optical;    Mesogenics;    Nano powders;    PDLC films;    Polymer dispersed liquid crystals;    Ultrasonic attenuation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/149/1/012202/pdf
DOI  :  10.1088/1757-899X/149/1/012202

来源: IOP

【 摘 要 】

The present study focuses on the relaxation processes in Cholesteric Liquid Crystal and mixtures. We have dispersed two different monomers in CLC to form Polymer dispersed liquid crystals (PDCLCs). PDLC films have a remarkable electro-optical behavior since they can be switched from highly light scattering state (OFF) to transparent state (ON) simply by application of an electric field. We have also doped ferroelectric nano - powder (NP) in CLC. The phase transitions occurred at temperatures lower than those exhibited by the mesogenic component before doping. The viscosity, ultrasonic velocity and density show variation with change in the material as well as temperature. The acoustic relaxation time and ultrasonic attenuation decrease with increase in temperature for CLC and CLC+NP. The parameters of PDCLC2 in comparison with PDCLC1 are more linear in isotropic and anisotropic regions. For PDCLC2 the values reach maximum value at the Cholesteric-isotropic transition.