Thorough elucidation and artificial control of the self-formation mechanism of the surface molecular alignment fabricated by means of slit-coater

2015 Fiscal Year Final Research Report

• Project/Area Number: 25390053
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied materials
• Research Institution: Nagaoka University of Technology
• Principal Investigator: Kimura Munehiro 長岡技術科学大学, 工学(系)研究科(研究院), 准教授 (20242456)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ネマティック液晶 / 液晶配向 / フレキシブルディスプレイ / 液中原子間力顕微鏡 / UV重合 / プレティルト角 / 配向印刷 / アンカリングエネルギー

Outline of Final Research Achievements

A novel method that utilizes a slit coater as a liquid crystal (LC) molecular alignment technique was studied. It was confirmed that the alignment transition from a planar alignment to a vertical alignment was caused by UV irradiation after LC coating when a certain UV-curable mesogen was doped with the nematic LC. From experimental results by means of atomic force microscope and surface energy measurement under the several conditions, it seems that the pretilt angle depends on the UV irradiation condition. UV-irradiation through a stripe-patterned photo-mask can make stripe-domain with vertical and planar alignment regions. It was also found that the azimuthal surface anchoring energy does not prevent degradation and is of the order of 10^-6～10^-5 J/m^2. We applied this method to fabricate liquid crystal display devices. Cholesteric liquid crystal with short helical pitch can be aligned uniformly and exhibits an electric field-induced tilt of optical axis with fast response speed.

Free Research Field

有機分子配向