Paper
25 August 2017 Homeotropic alignment of multiple bent-core liquid crystal phases using a polydimethylsiloxane alignment layer
Eric D. Carlson, Lee M. Foley, Edward Guzman, Eva D. Korblova, Rayshan Visvanathan, SeongHo Ryu, Min-Jun Gim, Michael R. Tuchband, Dong Ki Yoon, Noel A. Clark, David M. Walba
Author Affiliations +
Abstract
The control of the molecular orientation of liquid crystals (LCs) is important in both understanding phase properties and the continuing development of new LC technologies including displays, organic transistors, and electro-optic devices. Many techniques have been developed for successfully inducing alignment of calamitic LCs, though these techniques typically do not translate to the alignment of bent-core liquid crystals (BCLCs). Some techniques have been utilized to align various phases of BCLCs, but these techniques are often unsuccessful for general alignment of multiple materials and/or multiple phases. Here, we demonstrate that glass cells treated with polydimethylsiloxane (PDMS) thin films induce high quality homeotropic alignment of multiple mesophases of four BCLCs. On cooling to the lowest temperature phase the homeotropic alignment is lost, and spherulitic growth is seen in crystal and crystal-like phases including the dark conglomerate (DC) and helical nanofilament (HNF) phases. Evidence of homeotropic alignment is observed using polarized optical microscopy. We speculate that the methyl groups on the surface of the PDMS films strongly interact with the aliphatic tails of each mesogens, resulting in homeotropic alignment.
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Eric D. Carlson, Lee M. Foley, Edward Guzman, Eva D. Korblova, Rayshan Visvanathan, SeongHo Ryu, Min-Jun Gim, Michael R. Tuchband, Dong Ki Yoon, Noel A. Clark, and David M. Walba "Homeotropic alignment of multiple bent-core liquid crystal phases using a polydimethylsiloxane alignment layer", Proc. SPIE 10361, Liquid Crystals XXI, 1036118 (25 August 2017); https://doi.org/10.1117/12.2280569
Lens.org Logo
CITATIONS
Cited by 1 scholarly publication.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Liquid crystals

Birefringence

Optical alignment

Glasses

Crystals

Shape memory alloys

Thin films

Back to Top