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Updated: Aug 26, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Light Modulated Reversible "On-Off" Transformation of Arylazoheteroarene Based Discotics in Nematic Organization
Pravesh Kumar1, Indu Bala1, Ritobrata De1
1Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali Sector 81, SAS Nagar, Knowledge City Manauli, 140306, Punjab, India.
Abstract:
Three benzene-1,3,5-tricarboxamide (BTA) core-based molecular systems appended with phenylazo-3,5-dimethylisoxazole photoswitches at the peripheral position through variable-length alkoxy chains have been designed and synthesized. The supramolecular interactions of the mesogens provided discotic nematic liquid crystalline assembly as confirmed by polarized optical microscopy (POM) and X-ray diffraction (XRD) studies. Spectroscopic studies confirmed the reversible photoswitching and excellent thermal stability of the photoswitched states in solution phase and thin film. Also, atomic force microscopic (AFM) and POM investigations demonstrated the morphological changes in the self-assembly induced by the photoirradiation as monitored by the changes in the height profiles and optical appearance of the textures, respectively. Remarkably, the liquid crystalline discotic molecules showed reversible "on and off states" controlled by light at ambient temperature.
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