Orientational order parameter of liquid crystalline nanocomposites by Newton’s rings and image analysis methods
https://doi.org/10.17586/2220-8054-2019-10-3-243-254
Abstract
Liquid crystalline nanocomposites are prepared by dispersing TiO2, ZnO, Fe2O3 and Fe3O4 nanoparticles separately in 4-Cyano 4’-Propoxy-1, 1’-Biphenyl (3O-CB) liquid crystal in a 1:100 ratio. The characteristic textures exhibited are captured at different liquid crystalline phases by using POM. The phase transition temperatures are measured by both polarizing optical microscope (POM) and differential scanning calorimeter (DSC). The optical textures are analyzed by using MATLAB software to compute birefringence and order parameter of samples. The birefringence and order parameter also measured by conventional Newton’s rings technique, the results are discussed.
Keywords
liquid crystals,
nanocomposites,
optical textures,
phase transition temperatures,
birefringence,
order parameter
Supporting agencies: The authors are very much thankful to the management of Ghousia College of Engineering, Ramanagara, India and Bannari Amman Institute of Technology, Sathyamangalam, India for providing lab facilities to carry out this work. The authors also thankful to Dr. Dinesh Rangappa, VTU-PG centre, Muddenahalli, chikkaballapura Dist, Bengaluru, India for sponsoring nanoparticles.
About the Authors
H. M. Munavar
Department of Physics, KNS Institute of Technology
India
India
Munavar Hussain M.
Bengaluru
B. H. Doreswamy
Department of Physics, SJB Institute of Technology
India
India
Bengaluru
N. C. Shobha
Department of Physics, APS College of Engineering
India
India
Bengaluru
V. N. Vijayakumar
Department of Physics,Bannari Amman Institute of Technology
India
India
Sathyamangalam
K. Fakruddin
Department of Physics, Ghousia College of Engineering
India
India
Ramanagara
References
1. Kobayashi S., Miyama T., et al. Dielectric Spectroscopy of Metal Nanoparticle Doped Liquid Crystal Displays Exhibiting Frequency Modulation Response. J. Display Technology, 2006, 2, P. 121–129.
2. Garbovskiy Y., Glushchenko I. Nano-Objects and Ions in Liquid Crystals: Ion Trapping Effect and Related Phenomena. Crystals, 2015, 5 (4), P. 501–533.
3. Goel P. Arora M., Biradar A.M. Electro-optic switching in iron oxide nanoparticle embedded paramagnetic chiral liquid crystal via magnetoelectric coupling. Journal of Applied Physics, 2014, 115 (12), P. 124905(1–6).
4. Silva J.B., deBrito W., Mohallem N.D.S. Influence of heat treatment on cobalt ferrite ceramic powders. Materials Science and Engineering: B, 2004, 112 (2–3), P. 182–187.
5. Sun S., Murray C.B., et al. Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal super lattices. Science, 2000, 287 (5460), P. 1989–92.
6. Pankhurst Q.A., Connolly J., Jones S.K., Dobson J. Applications of magnetic nanoparticles in biomedicine. Journal of Physics D: Applied Physics, 2003, 36, P. R167–R181.
7. Ito A., Shinkai M., Honda H., Kobayashi T. Medical application of functionalized magnetic nanoparticles. J. BiosciBioeng, 2005, 100 (1), P. 1–11.
8. Avci N., Nesrullajev A., Oktik S. Nonlinear thermotropic and thermo- optical behaviour of planar oriented textures in nematic liquid crystals at phase transitions. Brazilian Journal of Physics, 2010, 40, P. 224–227.
9. Shin-Tson Wu, Uzi Efron, LaVerne D. Hess. Birefringence measurements of liquid crystals. Applied Optics, 1984, 23 (21), P. 3911–3915.
10. Fakruddin K., Jeevan Kumar R., Datta Prasad P.V., Pisipati V.G.K.M. Orientational Order Parameter – 1 A Birefringence Study. Molecular Crystals and Liquid Crystals, 2009, 511, P. 133–146.
11. Pardhasaradhi P., Datta Prasad P.V., et al. Orientational order parameter studies in two symmetric dimeric liquid crystals – an optical study. Phase Transitions, 2012, 85 (12), P. 1031–1044.
12. Gonzalez R.C., Woods R.E., Eddins S.L. Digital Image Processing Using MATLAB, 2nd Edition, Gates mark Publishing, Natick, 2009.
13. Solomon C., Breckon T. Fundamentals of Digital Image Processing: A Practical Approach with Examples in Matlab, Wiley-Blackwell, Chichester, U.K., 2011.
14. Priestley E.L., Wojtowicz P.J., Sheng P. Introduction to Liquid Crystals, RCA Laboratories, Princeton, NJ, 1974.
15. Kuczynski W., Zywucki B., Malecki J. Determination of orientational order parameter in various liquid-crystalline phases. Mol. Cryst. Liq. Cryst., 2002, 381, P. 1–19.
16. Zywicki B.J., Kuczynski W. IEEE transactions on optical phenomena – The orientational order in nematic liquid crystals from birefringence measurements. Dielectr. Electr. Insul., 2001, 8, P. 512–515.
17. Chandra Sekhar S. Liquid Crystals, Cambridge University Press: New York, 1992.
18. Singh S. Phase transitions in liquid crystals. Phys. Rep., 2000, 324, P. 107–269.
19. De Jeu W.H. Physical Properties of Liquid Crystalline Materials, Gordon and Breach, New York, 1980.
Review
For citations:
Munavar H.M., Doreswamy B.H., Shobha N.C., Vijayakumar V.N., Fakruddin K. Orientational order parameter of liquid crystalline nanocomposites by Newton’s rings and image analysis methods. Nanosystems: Physics, Chemistry, Mathematics. 2019;10(3):243-254. (In Russ.) https://doi.org/10.17586/2220-8054-2019-10-3-243-254
Views:
9
Email this article 