Orientation Direction Control in Liquid Crystalline Photoalignable Polymeric Films by Adjusting the Free-Surface Condition
journal contributionposted on 07.06.2016, 17:41 by Kazutoshi Miyake, Hiromi Ikoma, Makoto Okada, Shinji Matsui, Mizuho Kondo, Nobuhiro Kawatsuki
Adjusting the free-surface condition facilely controls the in-plane and out-of-plane orientations in liquid crystalline polymer (LCP) films. Top coating with aromatic molecules onto LC polymethacrylate films with N-benzylideneaniline (NBA) or 4-methoxybiphenyl (MB) side groups (PNBAM or PMBM) and subsequent annealing generate a random planar orientation while simultaneously removing the coated aromatic molecules, whereas annealing noncoated films induces a homeotropic orientation of the mesogenic side groups. Additionally, irradiating a top-coated PNBAM film with linearly polarized (LP) 365 nm light induces an in-plane molecular reorientation of the NBA side groups without changing the orientation in the homeotropically oriented region. Changes in the surface topology of the LCP films due to the reorientation processes are investigated in detail. Inkjet coating with aromatic molecules and LP 365 nm light exposure precisely controls the in-plane and out-of-plane alignment pattern in a PNBAM film.
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annealing noncoated films365 nm lightTop coatingside groupsPMBMLC polymethacrylate filmsreorientation processesOrientation Direction ControlPNBAM filmmesogenic side groupshomeotropic orientationLP 365 nm light exposureLCP filmsmoleculeNBA side groupsLiquid Crystalline Photoalignable Polymeric FilmsMBInkjet coatingsurface topology