화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.368, 4163-4170, 2001
Surface versus bulk anisotropy of photo-sensitive poly(vinyl cinnamate) alignmet layers
Reaction kinetics and orientational anisotropy of poly(vinyl cinnamate) (PVCN) alignment layers photo-co-polymerized with linearly polarized UV light were probed by measurements of linear dichroism (LD) and surface optical second-harmonic generation (SSHG). The results show that the bulk and the surface properties of PVCN films are very similar and suggest that in PVCN there are no specific surface photochemical processes, which could presumably reduce the anchoring of liquid crystals on PVCN substrates. The azimuthal surface anchoring energy coefficient of nematic liquid crystal 5CB in contact with our substrates was of the order of 10(-6) J/m(2) and strongly depended on the procedure used to measure it. This can be explained by a presence of various memory effects on the LC/PVCN interface, which strongly affect the alignment ability of the PVCN layers.