Effect of ion trapping behavior of TiO2 nanoparticles on different parameters of weakly polar nematic liquid crystal
Tóm tắt
In the present investigation, TiO2-doped weakly polar nematic liquid crystal (NLC) has been studied. This study mainly focuses on dielectric, electro-optical and optical properties of pure NLC and doped systems. Variation in different parameters like dielectric permittivity, dielectric loss, dielectric anisotropy and conductivity has been noticed. Permittivity of the doped system is almost the same as undoped system. With doping concentration, the ionic contribution to the dielectric loss as observed in low-frequency region has been suppressed and the shift in relaxation frequency toward higher frequency side has also been observed. The electrical conductivity and threshold voltage have been decreased with increasing concentration of nanoparticles (NPs). The continuous increase in dielectric anisotropy with increasing the concentration of NPs has also been observed. These results have been attributed to the trapping capability of free ions by TiO2 NPs. Further, we focused on the study of photoluminescence (PL), UV absorbance and Fourier transformed infrared spectroscopy (FTIR) of pure and doped systems. The continuous increase in PL intensity without any shift in emission peak has been observed for doped systems. Enhancement in UV absorbance with increasing concentration of NPs has also been observed. The effect of NPs doping on molecular dynamics of NLC can be clearly seen by FTIR study. The results suggest that the TiO2 NP-doped weakly polar NLC can have significant improved dielectric, electro-optical and optical properties. This makes the weakly polar NLC to be a potential candidate for many applications.
Tài liệu tham khảo
Schadt, M.: Nematic liquid crystals and twisted-nematic LCDs. J. Liq. Cryst. 42(5–6), 646–652 (2015)
Lin, Y.-H., Wang, Y.-J., Reshetnyak, V.: Liquid crystal lenses with tunable focal length. Liq Cryst Rev 5(2), 111–143 (2017)
Abdulhalim, I.: Non-display bio-optic applications of liquid crystals. Liq. Cryst. Today 20(2), 44–60 (2011)
De Sio, L., Roberts, D.E., Liao, Z., Hwang, J., Tabiryan, N., Steeves, D.M., Kimball, B.R.: Beam shaping diffractive wave plates. Appl. Opt. 57(1), A118–A121 (2018)
Geis, M.W., Bos, P.J., Liberman, V., Rothschild, M.: Broadband optical switch based on liquid crystal dynamic scattering. Opt. Express 24, 13812–13823 (2016)
Konshina, E.A., Shcherbinin, D.P.: Study of dynamic light scattering in nematic liquid crystal and its optical, electrical and switching characteristics. Liq. Cryst. 45, 292–302 (2018)
Ghandevosyan, A.A., Hakobyan, R.S.: Decrease in the threshold of electric Freedericksz transition in nematic liquid crystals doped with ferroelectric nanoparticles. J. Contemp. Phys. 47, 33–35 (2012)
Iranizad, E.S., Dehghani, Z., Nadafan, M.: Nonlinear optical properties of nematic liquid crystal doped with different compositional percentage of synthesis of Fe3O4 nanoparticles. J. Mol. Liq. 190, 6–9 (2014)
Bian, H., Yao, F., Gao, Y., Pei, Y., Zhang, J., Sun, X.: Random lasing in unbounded dye-doped nematic liquid crystals. Liq. Cryst. 43, 581–586 (2015)
Pathak, G., Agrahari, K., Yadav, G., Srivastava, A., Strzezysz, O., Manohar, R.: Tuning of birefringence, response time, and dielectric anisotropy by the dispersion of fluorescent dye into the nematic liquid crystal. Appl. Phys. A 124(7), 463–472 (2018)
Siarkowska, A., Chychłowski, M., Budaszewski, D., Jankiewicz, B., Bartosewicz, B., Wolińsk, T.R.: Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles. Beilstein J. Nanotechnol. 8, 2790–2801 (2017)
Hsu, C.-J., Lin, L.-J., Huang, M.-K., Huang, C.-Y.: Electro-optical effect of gold nanoparticle dispersed in nematic liquid crystals. Crystals 7(10), 287–297 (2017)
Singh, G., Fisch, M.: Emissivity and electrooptical properties of semiconducting quantum dots/rods and liquid crystal composites: a review. Rep. Prog. Phys. 79, 056502 (2016)
Manohar, R., Yadav, S.P., Srivastava, A.K., Mishra, A.K., Pandey, K.K., Sharma, P.K., Pandey, A.C.: Zinc oxide (1% Cu) nanoparticle in nematic liquid crystal: dielectric and electro-optical study. Jpn. J. Appl. Phys. 48, 101501 (2009)
Vimal, T., Singh, D.P., Gupta, S.K., Pandey, S., Agrahari, K., Manohar, R.: Thermal and optical study of semiconducting CNTs-doped nematic liquid crystalline material. Phase Transit. 89(6), 632–642 (2016)
Al-Zangana, S., Turner, M., Dierking, I.: A comparison between size dependent paraelectric and ferroelectric BaTiO3 nanoparticle doped nematic and ferroelectric liquid crystals. J. Appl. Phys. 121, 085105 (2017)
Kim, G.Y., Kwak, C.H.: Study on the optical characteristics of various quantum-dot-doped nematic liquid crystals. New Phys. Sae Mulli 68, 173–180 (2018)
Garbovskiy, Y.: Kinetics of ion-capturing/ion-releasing processes in liquid crystal devices utilizing contaminated nanoparticles and alignment films. Nanomaterials 8, 59–70 (2018)
Tomylko, S., Yaroshachuk, O., Kovalchuk, O., Maschke, U., Yamaguchi, R.: Dielectric properties of nematic liquid crystal modified with diamond nanoparticles. Ukr. J. Phys. 57(2), 239–243 (2012)
Garbovskiy, Y., Glushchenko, I.: Nano-objects and ions in liquid crystals: ion trapping effect and related phenomena. Crystals 5, 501–533 (2015)
Klimusheva, G., Mirnaya, T., Garbovskiy, Y.: Versatile nonlinear-optical materials based on mesomorphic metal alkanoates: design, properties, and applications. Liq. Cryst. Rev. 3, 28–57 (2015)
Garbovskiy, Y.: Nanoparticle-enabled ion trapping and ion generation in liquid crystals. Adv. Condens. Matter Phys. 8, 8914891 (2018)
Garbovskiy, Y.: Nanoparticle enabled thermal control of ions in liquid crystals. Liq Cryst. 44(6), 948–955 (2016)
Wu, P.C., Lisetski, L.N., Lee, W.: Suppressed ionic effect and low-frequency texture transitions in a cholesteric liquid crystal doped with graphene nanoplatelets. Opt. Express 23, 11195–11204 (2015)
Hsiao, Y.G., Huang, S.M., Yeh, E.R., Lee, W.: Temperature-dependent electrical and dielectric properties of nematic liquid crystals doped with ferroelectric particles. Displays 44, 61–65 (2016)
Garbovskiy, Y.: Switching between purification and contamination regimes governed by the ionic purity of nanoparticles dispersed in liquid crystals. Appl. Phys. Lett. 108, 121104 (2016)
Garbovskiy, Y.: Ions in liquid crystals doped with nanoparticles: conventional and counterintuitive temperature effects. Liq. Cryst. 44(9), 1402–1408 (2017)
Liu, Y., Claus, R.O.: Blue light emitting nanosized TiO2 colloids. J. Am. Chem. Assoc. 119, 5273–5277 (1997)
Joshi, T., Kumar, A., Prakash, J., Biradar, A.M., Hasse, W.: Low power operation of ferroelectric liquid crystal system dispersed with zinc oxide nanoparticles. Appl. Phys. Lett. 96, 253109 (2009)
Shcherbinin, D.P., Konshina, E.A.: Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals. Beilstein J. Nanotechnol. 8, 2766–2770 (2017)
Tang, C.Y., Huang, S.M., Lee, W.: Electrical properties of nematic liquid crystals doped with anatase TiO2 nanoparticles. J. Phys. D Appl. Phys. 44, 355102 (2011)
Chen, W.T., Chen, P.S., Chao, C.Y.: Effect of doped insulating nanoparticles on the electro-optical characteristics of nematic liquid crystals. Jpn. J. Appl. Phys. 48, 015006 (2009)
Lee, W.-K., Choi, J.-H., Na, H.-J., Lim, J.-H., Han, J.-M., Hwang, J.-Y., Seo, D.-S.: Low-power operation of vertically aligned liquid-crystal system via anatase–TiO2 nanoparticle dispersion. Opt. Lett. 34, 3653–3655 (2009)
Yadav, S.P., Manohar, R., Singh, S.: Effect of TiO2 nanoparticles dispersion on ionic behaviour in nematic liquid crystal. Liq. Cryst. 42, 1095–1101 (2015)
Roy, J.S., Majumder, T.P., Dabrowski, R.: Enhanced photoluminescence in CdS nanorods doped with antiferroelectric liquid crystals. J. Lumin. 148, 330–333 (2014)
Pathak, G., Pandey, S., Katiyar, R., Dbrowski, R., Garbat, K., Manohar, R.: Analysis of photoluminescence, UV absorbance, optical band gap and threshold voltage of TiO2 nanoparticles dispersed in high birefringence nematic liquid crystal towards its application in display and photovoltaic devices. J. Lumin. 192, 33–39 (2017)
Oka, A., Singha, G., Glorieux, C., Thoen, J.: Broadband dielectric studies of weakly polar and non-polar liquid crystals. Liq. Cryst. 31(1), 31–38 (2004)
Gupta, S.K., Singh, D.P., Manohar, R.: Electrical and polarization behaviour of titania nanoparticles doped ferroelectric liquid crystal. Adv. Mater. Lett. 6(1), 68–72 (2015)
Pathak, G., Katiyar, R., Agrahari, K., Srivastava, A., Dabrowski, R., Garbat, K., Manohar, R.: Analysis of birefringence property of three different nematic liquid crystals dispersed with TiO2 nanoparticles. Opto Electron. Rev. 26(1), 11–18 (2018)
Ardakani, H.: Electrical and optical properties of in situ “hydrogen-reduced” titanium dioxide thin films deposited by pulsed excimer laser ablation. Thin Solid Films 248(2), 234–239 (1994)
Kress, H.: Dielectric behavior of liquid crystals. Adv. Liq. Cryst. 6, 109 (1983)
Clark, M.G., Leslie, F.M.: A calculation of orientational relaxation in nematic liquid crystals. Proc. R. Soc. Lond. A 361, 463–485 (1978)
Tripathi, P.K., Misra, A.K., Manohar, S., Gupta, S.K., Manohar, R.: Improved dielectric and electro-optical parameters of ZnO nano-particle (8% Cu2+) doped nematic liquid crystal. J. Mol. Struct. 1035, 371–377 (2013)
Paxton, A.T., Thiên-Nga, L.: Electronic structure of reduced titanium dioxide. Phys. Rev. B 57, 1579 (1998)