Polymeric-nanoparticles–induced vertical alignment in ferroelectric liquid crystals

¹  Liquid Crystal Group, National Physical Laboratory - Dr. K. S. Krishnan Road, New Delhi-110012, India
²  Conducting Polymer Group, National Physical Laboratory - Dr. K. S. Krishnan Road, New Delhi-110012, India
³  Department of Physics and Astrophysics, University of Delhi - Delhi-110007, India

Corresponding author: abiradar@mail.nplindia.ernet.in

Received: 13 July 2009
Accepted: 5 October 2009

Abstract

Here, we report the polymeric (copolymer of benzene and pentacene) nanoparticles (PNPs) induced vertical alignment in ferroelectric liquid crystals (FLCs). The nanoparticles used in this study have been synthesized via chemical route method. The PNPs have been doped in FLC mixture. It has been observed that pentacene molecules (presented in PNPs used) prefer an upright orientation on the indium-tin-oxide–coated surfaces, which in turn provide assistance to align FLC molecules vertically (or homeotropically). It has also been observed that the addition of PNPs into the FLC materials improves the electro-optical response. However, the transition temperatures of the PNPs-doped FLC materials have been lowered. These findings will provide a fascinating tool to align FLC materials devoid of any surface treatment. Moreover, these studies would be helpful in the realization of low threshold and faster liquid crystal display devices.