Abstract
We proposed a method for enhancing the planar orientation of reactive mesogen (RM) molecules by means of anisotropic plasma treatment. Anisotropic surface plasma, of which energy density is dependent on the azimuthal angle, was generated by column-shaped ceramic electrodes. The anisotropic plasma was discharged on the surface of a polyvinyl alcohol (PVA) alignment layer before the rubbing process began. The contact angle of the surface was increased from 12° to 83° after plasma treatment, indicating a hydrophobic property of the surface. From the atomic force microscopy (AFM) measurement, it was found that the grain size of the PVA layer was reduced and that the grooved patterns were formed provided that the plasma direction was parallel to the rubbing direction of the surface. Consequently, the planar orientation was enhanced, and the in-plane retardation of the photo-polymerized RM films increased when the parallel plasma was treated on the surface.
Highlights
Optical retarder films have been widely used in the display devices [1,2,3]
8 shows the contact angle property of the PVAofalignment molecules, we investigated the changes of the surface properties using contact angle measlayer with different surface treatment conditions
Because the contact angle is dependent both on the chemical structure and the physical morphology, we investigated the FT-IR (Figure 10) and the atomic force microscopy (AFM) topography of the substrate to verify the physical reason for this (Figure 10)
Summary
Optical retarder films have been widely used in the display devices [1,2,3]. Commercial retarder films for display devices can be classified into the stretched film type [4,5,6] and the reactive mesogen (RM) type [7,8,9]. The smectic RM molecules show greater order parameters than the nematic RM molecules, the homeotropic orientation at the air interface limits their application in the coatable polarizer and in the retarder film [16,17,18]. Crystals 2021, 11, 1080 order parameters than the nematic RM molecules, the homeotropic orientation at the air interface limits their application in the coatable polarizer and in the retarder film [16,17,18]. In the previous literature [23], it was reported that a planar alignment could be induced induced by the oblique incidence of plasma This result implies that some physical anisotby the incidence of surface plasma.by.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
