A Comparative Study on Electro-Optic Effects of Organic N-benzyl-2-methyl-4-nitroaniline and Morpholinium 2-Chloro-4-nitrobenzoate Doped in Nematic Liquid Crystals E7

Polymers

Pravinraj Selvaraj¹  Karthick Subramani²  Chi-Yen Huang³  Che-Ju Hsu³ 

[1] Department of Physics, National Changhua University of Education, Changhua 500, Taiwan;Department of Physics, University College of Engineering, BIT-Campus, Anna University, Tiruchirappalli 620 024, India;Graduate Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan;

关键词: organic molecule;    N-benzyl-2-methyl-4-nitroaniline (BNA);    morpholinium 2-chloro-4-nitrobenzoate (M2C4N);    liquid crystal;    density functional theory;   

DOI  :  10.3390/polym12122977

来源: DOAJ

【 摘 要 】

Improvements in electro-optical responses of LC devices by doping organic N-benzyl-2-methyl-4-nitroaniline (BNA) and Morpholinium 2-chloro-4-nitrobenzoate (M2C4N) in nematic liquid crystals (LCs) have been reported in this study. BNA and M2C4N-doped LC cells have the fall time that is fivefold and threefold faster than the pristine LC cell, respectively. The superior performance in fall time of BNA-doped LC cell is attributed to the significant decrements in the rotational viscosity and threshold voltage by 44% and 25%, respectively, and a strong additional restoring force resulted from the spontaneous polarization electric field of BNA. On the other hand, the dielectric anisotropy (Δε) of LC mixture is increased by 16% and 6%, respectively, with M2C4N and BNA dopants. M2C4N dopant induces a large dielectric anisotropy, because the phenyl-amine/hydroxyl in M2C4N induces a strong intermolecular interaction with LCs. Furthermore, BNA dopant causes a strong absorbance near the wavelength of 400 nm that filters the blue light. The results indicate that M2C4N doping can be used to develop a high Δε of LC mixture, and BNA doping is appropriate to fabricate a fast response and blue-light filtering LC device. Density Functional Theory calculation also confirms that BNA and M2C4N increase the dipole moment, polarization anisotropy, and hence Δε of LC mixture.

【 授权许可】

Unknown