Optical Properties of ZnO Dispersed p-n-Decyloxy Benzoic Acid Liquid Crystals

This paper deals with the birefringence and order parameter calculation of liquid crystalline (LC) materials like p-n-decyloxy (10OBA) benzoic acid with the incorporation of ZnO nanoparticles (NPs) in different low wt.% concentrations (0.5–2 wt.%). From the characterization techniques, it is evident that ZnO NPs in 10OBA results in significant changes in optical properties such as refractive index (RI), birefringence (δn) and order parameter (S). The observations suggest that, because of their larger size and higher dipole moments compared to the nematic LC molecules, ZnO NPs generate a higher torque. This torque facilitates the orientation of the LC molecules, leading to increased birefringence and improved ordering within the LC system. The order parameter values are calculated using four optical methods – Kuczynksi, Haller, Effective geometry, and Vuks – at a stabilized nematic region in the visible range at 435, 500, 570, and 635 nm wavelengths. The values of dispersive powers are also increased for the 10OBA with ZnO NPs in various concentrations. The results suggest that the materials can be used in liquid crystal displays and tunable lenses.

1. P. J. Collings, M. Hird, Introduction to Liquid Crystals Chemistry and Physics, Taylor & Francis, London (1997).

2. K. Goossens, Chem. Rev., 116, 4643–4807 (2016).

3. C. A. Brackett, IEEE Areas Commun., 8, 948–964 (1990).

4. L. Zhu, G. Zhu, A. Wang, L. Wang, J. Ai, S. Chen, C. Du, J. Liu, S. Yu, J.Wang, Opt. Lett., 43, 1890–1893 (2018).

5. N. Panwar, S. Sharma, A. K. Singh, Phys. Commun., 18, 64–84 (2016).

6. S. Dutt, P. F. Siril, S. Remita, RSC Adv., 7, 5733–5750 (2017).

7. S. Ghosh, L. Ramos, H. Remita, Nanoscale, 10, 5793–5819 (2018).

8. M. D. Lynch, D. L. Patrick, Nano Lett., 2, 1197–1201 (2002).

9. R. Basu, G. Iannacchione, Appl. Phys. Lett., 106, 124312 (2009).

10. A. Malik, A. Choudhary, P. Silotia, A. M. Biradar, J. Appl. Phys., 110, 064111 (2011).

11. H. Jiang, N. Toshima, Chem. Lett., 38, 566–567 (2009).

12. L. J. Martinez-Miranda, K. M. Traister, Z. I. Meléndez-Rodríguez, L. Salamanca-Riba, J. Appl. Phys. Lett., 97, 223301 (2011).

13. F. Brochard, P. G. de Gennes, J. Phys. France, 31, 691–708 (1970).

14. I. Dierking, G. Scalia, P. Morales, D. LeClere, Adv. Mater., 16, No. 11, 865–869 (2004).

15. I. Dierking, G. Scalia, P. J. Morales, J. Appl. Phys., 97, 044309 (2005).

16. J. CLoudet, P. Barois, P. Poulin, Nature, 407, 611–613 (2013).

17. L. J. Martínez-Miranda, L. Kurihara, J. Appl. Phys., 105, 084305 (2009).

18. S. Supreet, S. Kumar, K. Raina, R. Pratibha, Liq. Cryst., 40, 228–236 (2013).

19. N. Pushpavathi, K. L. Sandhya, S. Krishna Prasad, J. Mol. Liq., 302, 112571 (2020).

20. F. Li, O. Buchnev, C. I. Cheon, et al., Phys. Rev. Lett., 97, 147801 (2006).

21. J. P. F. Lagerwall, G. Scalia, Curr. Appl. Phys., 12, 1387–1412 (2012).

22. H. Y. Jung, H. J. Kim, S. Yang, Y. G. Kang, B. Y. Oh, H. G. Park, D. S. Seo, Liq. Cryst., 39, 789–793 (2012).

23. H. J. Kim, Y. G. Kang, H. G. Park, K. M. Lee, S. Yang, H. Y. Jung, D. S. Seo, Liq. Cryst., 38, 871–875 (2011).

24. Y. A. Nastishin, H. Liu, T. Schneider, V. Nazarenko, R. Vasyuta, S. V. Shiyanovskii, O. D. Lavrentovich, Phys. Rev. E, 72, 041711 (2005).

25. A. Kumar, R. Manohar, Liq. Cryst., 39, 889–897 (2012).

26. L. Isa, E. Amstad, K. Schwenke, E. D. Gado, Patrick Ilg, Martin Kroger, E. Reimhult, Soft Matter, 7, 7663–7675 (2011).

27. M. Tejaswi, P. Pardhasaradhi, B. T. P. Madhav, M. C. Rao, N. Krishna Mohan, R. K. N. R. Manepalli, Liq. Cryst., 47, 918–938 (2020).

28. D. Venkata Rao, P. Pardhasaradhi, V. G. K. M. Pisipati, P. V. Datta Prasad, Phase Trans., 623, 87–103 (2015).

29. P. Jayaprada, P. Pardhasaradhi, B. T. P. Madhav, K. Krishna Reddy, D. Rama Sekhara Reddy, G. Giridhar, M. C. Rao, R. K. N. R. Manepalli, Z. Naturforsch., 76, 75–98 (2021).