Vertical alignment of liquid crystals on plant-based vanillin derivative-substituted polystyrene films

Dopant-Enhanced Vertical Alignment of Negative Liquid Crystals

A simple method for achieving high-contrast vertical alignment of high birefringence (Dn 0.28) negative dielectric anisotropic liquid crystal mixture using buffed polyimide substrates is demonstrated. By doping a positive, or non-polar dielectric anisotropic compound or mixture to the laterally difluorinated tolane liquid crystal host, an excellent vertical alignment was obtained. This alignmen...

Alignment of Liquid Crystals on Polyimide Films Exposed To Ultraviolet Light

The influence of unpolarized and linearly polarized UV exposure on previously rubbed as well untreated thin polyimide ͑PI͒ alignment layers was studied. Optical retardation and surface morphology measurements were carried out to understand the nature of surface modification as a function of the polarization and the exposure time of the UV light under different surface conditions. The exposure of ...

Growth Shape of Isotactic Polystyrene Crystals in Thin Films

The crystal growth of isotactic polystyrene (it-PS) is investigated in very thin, 11 nm thick films. The it-PS crystals grown in the thin films show quite different morphology from that in the bulk. With decreasing crystallization temperature, the branching morphology in a diffusion field appears: dendrite and compact seaweed. The branching morphology is formed through a morphological instabili...

Substrate-induced bulk alignment of liquid crystals.

Photo-Induced Vertical Alignment of Liquid Crystals via In Situ Polymerization Initiated by Polyimide Containing Benzophenone

Vertical alignment of liquid crystal (LC) was achieved in an easy and effective way: in situ photopolymerization of dodecyl acrylate (DA) monomers initiated by polyimide based on 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and 3,3′-dimethyl-4,4′-diaminodiphenyl methane (BTDA-DMMDA PI). The alignment behavior and alignment stabilities were characterized by a polarizing optical microscope (...