Browsing by Author "Hegde, H."

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Light Sensitive Molecule for Photonic Devices
(Wiley-VCH Verlag, 2015) Hegde, H.; Fernandes, P.Z.; Yuvaraj, A.R.; Mei, G.S.; Lutfor, M.R.; Mohd Yusoff, M.M.
Summary Light induced effects on rod and bent shaped liquid crystals with azobenzene moiety were investigated using UV/Vis spectrophotometer. Study revealed that shape of the structure influenced their relaxation behavior in that fast thermal back relaxation in rod shape (monoazo substitution) form, while long thermal back relaxation in bent shape forms (diazo substitution). Both relaxation times are useful for creation of optical rewritable boards, optical storage devices, etc. Â© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Photo tuning of thiophene-2,5-dicarbohydrazide derivatives for their photoalignment ability-molecular modelling studies
(Royal Society of Chemistry, 2015) Hegde, H.; Murausky, A.A.; Murauski, A.A.; Kukhta, I.N.; Vasudeva Adhikari, A.V.; Komitov, L.
In this work, we reported a photoalignment of a nematic liquid crystal, promoted by thin alignment layers made from novel thiophene-2,5-dicarbohydrazide derivatives after being illuminated with linear polarized UV light. A clear indication of the relationship between the molecular structure and alignment properties of the materials was obtained by introducing a methyl substituent group (-CH3) in the molecular structure of some of the materials studied in this work. Interestingly, the illumination with linear polarized UV caused the preferred direction of liquid crystal alignment, promoted by these layers, to be oriented either parallel (in the case of the thiophene derivative without methyl substitution) or perpendicular (in the case of the thiophene derivative with methyl substitution). The mechanism behind the observed alignment effect is elucidated by molecular modelling studies. These studies suggested the change of the orientation of the molecular net dipole moment, when a methyl group is incorporated in the molecular structure of the materials, as a possible origin. Such information is indispensable for the design and synthesis of novel photo-alignment materials for liquid crystal displays of high quality. © The Royal Society of Chemistry 2015.
Polarity dependent photoisomerization of ether substituted azodyes: Synthesis and photoswitching behavior
(Elsevier, 2015) Gan, S.M.; Pearl, Z.F.; Yuvaraj, A.R.; Lutfor, M.R.; Hegde, H.
Two new ether substituted azodyes were synthesized and characterized by different spectral analysis such as 1H NMR, 13C NMR, FTIR and UV/Vis. Synthesized compounds were used to study the photoisomerization phenomenon by using UV-Vis spectro-photometer. Interesting polarity dependent effect is observed for the first time on these materials. Trans-cis (E-Z) and cis-trans (Z-E) conversion occurred within 41 s and 445 min, respectively for both the compounds in solutions. Polarizing optical microscopy studies revealed that there is no liquid crystal phase for both the compounds. The dramatic variation in the optical property is speculated to be the polarity of the chemical species. These derivatives are useful to fabricate optical data storage devices. © 2015 Published by Elsevier B.V.