Surface modification of a poly(ethylene-co-vinyl acetate) layer by ion beam irradiation for the uniform alignment of liquid crystals
- Authors
- 이동욱; 이주환; 김은미; 허기석; 김동현; Oh, Jin Young; Yang Liu; Dae-Shik SEO
- Issue Date
- Oct-2021
- Publisher
- ELSEVIER SCIENCE BV
- Keywords
- PEVA; Liquid crystals; Ion beam
- Citation
- JOURNAL OF MOLECULAR LIQUIDS, v.339, pp 116700-1 - 116700-7
- Journal Title
- JOURNAL OF MOLECULAR LIQUIDS
- Volume
- 339
- Start Page
- 116700-1
- End Page
- 116700-7
- URI
- https://yscholarhub.yonsei.ac.kr/handle/2021.sw.yonsei/6757
- DOI
- 10.1016/j.molliq.2021.116700
- ISSN
- 0167-7322
- Abstract
- The post-processing of a poly(ethylene-co-vinyl acetate) (PEVA) film by ion-beam (IB) irradiation is
described herein for use as a liquid crystal (LC) alignment layer. Various film curing temperatures are
investigated in order to achieve a stable film prior to IB irradiation, and a uniform and homogeneous
LC alignment with superior optical transparency is obtained at a curing temperature of 130 C. The chemical
and morphological effects of IB irradiation are further examined by X-ray photoelectron spectroscopy
(XPS) and atomic force microscopy (AFM). Although the surface morphology exhibits a random pattern,
the IB irradiation is found to modify the chemical characteristics of the PEVA surface by simultaneously
inducing van der Waals forces and strong dipole-dipole interactions with the LCs, thus leading to unidirectional
LC alignment. In addition, LC cells are fabricated from the IB-irradiated PEVA films, and the LC
alignment state is confirmed by polarized optical microscopy and pre-tilt angle measurements. Further,
the high transparency of the deposited PEVA film compared to that of ITO-coated glass is demonstrated
via transmittance measurement. In view of this superior performance, the IB-irradiated PEVA film is a
promising alternative for advanced LC displays.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - College of Engineering > Electrical and Electronic Engineering > 1. Journal Articles
Items in Scholar Hub are protected by copyright, with all rights reserved, unless otherwise indicated.