The Synthesis and Phase Behavior of a Novel Discoticnematic Triphenylene Mesogen and its Application to an Optically Anisotropic Film
A novel discotic triphenylene derivative bearing one triphenylene discogen as core and three cyano-biphenyl moieties was synthesized and its thermal behavior was studied using polarizing optical microscope, differential scanning calorimeter and X-ray diffraction. It was found that this molecule containing [decylene?] spacers showed nematic phase. After being mixed with methyl methacrylate (MMA), the discogen showed nematic phase at the mesophase temperature range (64~85 °C) and oriented spontaneously in the mixture after annealing for 2 hours in the mixture. The orientation can be stabilized by the polymerization of MMA. The orientation can be fixed by the polymerization of MMA. It was treated directly on glass substrate, which surface did not treat by polyimide film and confirmed the orientation was proved by X-ray diffraction. This offers If the alignment of the discotic molecules can be freely controlled and fixed, a useful mean to produce new area of optically anisotropic film will be produced with this material.
M.K. Lei, X.P. Zhu, K.W. Xu and B.S. Xu
C. X. Zhang, Z. Q. He, J. L. Pu, J. J. Wang, Y. S. Wang, Z. X. Li, S. Ye, "The Synthesis and Phase Behavior of a Novel Discoticnematic Triphenylene Mesogen and its Application to an Optically Anisotropic Film", Key Engineering Materials, Vols. 373-374, pp. 678-681, 2008