Prenematic Self-Assembling of Mesogenic Molecules in Isotropic Liquid and Orientational Order in Nematic Phase

• Authors: E. Wolarz , D. Bauman , J. Jadżyn , R. Dąbrowski
• Languages of publication: EN

Abstracts

EN

Dielectric relaxation study of nematogenic 4-n-alkyl-4'-cyanobiphenyls (nCB, n = 5, 6), 4-(trans-4'-n-alkylcyclohexyl)isothiocyanatobenzenes (nCHBT, n = 6, 8), 4-cyanophenyl-4'-n-alkylbenzoates (nCPB, n = 6, 8), 4-cyano-3-fluorophenyl-4'-n-octyloxybenzoate (8OCFPB), and 4-cyanophenyl-4'-n-octyloxy-3'-fluorobenzoate (8OCPFB) was performed in the frequency range from 50 kHz to 100 MHz in the nematic and isotropic phases. The static permittivity and the relaxation process related to the rotation of molecules around their short axis was analyzed. For some of these liquid crystals anomalous temperature dependence of static permittivity in the pretransitional region of the isotropic phase was observed. Based on the Meier-Saupe-Martin model of molecular diffusion in nematics, the orientational order parameter 〈P_2〉 was determined from dielectric relaxation times and retardation factor. The values of 〈P_2〉 calculated from the dielectric relaxation data were compared with the results obtained from measurements of polarized electronic absorption. Correlations between the magnitude of the dielectric pretransitional effect and the orientational order in the nematic phase were discussed.

Keywords

EN

42.70.Df; 61.30.Gd; 77.22.Ch

Discipline

• 61.30.Gd: Orientational order of liquid crystals; electric and magnetic field effects on order
• 77.22.Ch: Permittivity (dielectric function)(for low-permittivity dielectric films, see 77.55.Bh; for high-permittivity gate dielectric films, 77.55.D-)
• 42.70.Df: Liquid crystals(for structure of liquid crystals, see 61.30.-v)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2011
• Volume: 120
• Issue: 3
• Pages: 447-454

Dates

published

2011-09

received

2010-09-20

(unknown)

2011-04-28

Contributors

author

E. Wolarz

• Faculty of Technical Physics, Poznań University of Technology, Nieszawska 13a, 60-965 Poznań, Poland

author

D. Bauman

• Faculty of Technical Physics, Poznań University of Technology, Nieszawska 13a, 60-965 Poznań, Poland

author

J. Jadżyn

• Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland

author

R. Dąbrowski

• Institute of Chemistry, Military University of Technology, S. Kaliskiego 1, 00-950 Warszawa, Poland

References

• 1. P.G. de Gennes, The Physics of Liquid Crystals, Clarendon Press, Oxford 1975
• 2. G.R. Luckhurst, in: The Molecular Physics of Liquid Crystals, Eds. G.R. Luckhurst, G.W. Gray, Academic Press, London 1979, p. 85
• 3. J. Jadżyn, P. Kędziora, L. Hellemans, in: Relaxation Phenomena in Dielectric, Magnetic and Superconducting Materials, Eds. W. Haase, S. Wróbel, Springer-Verlag, Heidelberg 2003, p. 51
• 4. C.J.F. Boettcher, Dielectrics in Static Fields, Theory of Electric Polarisation, Vol. 1, Elsevier Scientific Publishing Company, Amsterdam 1973
• 5. M.J. Bradshaw, E.P. Raynes, Mol. Cryst. Liq. Cryst. Lett. 72, 73 (1981)
• 6. J. Jadżyn, G. Czechowski, J.L. Déjardin, M. Ginovska, J. Phys. Chem. A 111, 8325 (2007)
• 7. J. Jadżyn, U. Sokołowska, J.L. Déjardin, J. Phys. Chem. B 112, 9050 (2008)
• 8. B. Van Roie, J. Leys, K. Denolf, C. Glorieux, G. Pitsi, J. Thoen, Phys. Rev. E 72, 041702 (2005)
• 9. M. Janik, S.J. Rzoska, A. Drozd-Rzoska, J. Zioło, P. Janik, S. Maślanka, K. Czupryński, J. Chem. Phys. 124, 144907 (2006)
• 10. A. Drozd-Rzoska, S. Pawlus, S.J. Rzoska, Phys. Rev. E 64, 051701 (2001)
• 11. A. Drozd-Rzoska, S.J. Rzoska, J. Zioło, J. Jadżyn, Phys. Rev. E 63, 052701 (2001)
• 12. P. Ehrenfest, Proc. R. Acad. Sci. Amsterdam 36, 153 (1933)
• 13. N. Bielejewska, E. Chrzumnicka, E. Mykowska, R. Przybylski, M. Szybowicz, K. Władysiak, D. Bauman, Acta Phys. Pol. A 110, 777 (2006)
• 14. A. Modlińska, D. Bauman, J. Jadżyn, R. Dąbrowski, Z. Naturforsch. 66a, 251 (2011)
• 15. H. Khoshsima, H. Tajalli, A. Ghanadzadeh, R. Dąbrowski, Mol. Cryst. Liq. Cryst. 460, 93 (2006)
• 16. J. Jadżyn, G. Czechowski, J.L. Déjardin, J. Phys. Chem. B 112, 4948 (2008)
• 17. K.S. Cole, R.H. Cole, J. Chem. Phys. 9, 341 (1941)
• 18. G. Czechowski, J. Jadżyn, J. Zioło, S.J. Rzoska, M. Paluch, Z. Naturforsch. 57a, 244 (2002)
• 19. J. Jadżyn, G. Czechowski, R. Douali, C. Legrand, Liq. Cryst. 26, 1591 (1999)
• 20. D. Dunmur, K. Toriyama, in: Physical Properties of Liquid Crystals, Ed. D. Demus, J. Goodby, G.W. Gray, H.W. Spiess, V. Vill, Willey VCH, Weinheim 1999, p. 129
• 21. D. Bauman, J. Jadżyn, A. Zajczyk, R. Dąbrowski, Soft Materials 8, 89 (2010)
• 22. J. Czub, R. Dąbrowski, S. Urban, Phase Transit. 80, 631 (2007)
• 23. V.I. Minkin, O.A. Osipov, Y.F. Ždanov, Dipole Moments in Organic Chemistry, Izd. Khimiya, Moskva 1968 (in Russian)
• 24. D. Bauman, J. Jadżyn, E. Wolarz, A. Modlińska, R. Dąbrowski, Opto-Electron. Rev. 18, 63 (2010)
• 25. A. Drozd-Rzoska, J. Chem. Phys. 130, 234910 (2009)
• 26. A.J. Martin, G. Meier, A. Saupe, Symp. Faraday Soc. 5, 119 (1971)
• 27. G. Meier, A. Saupe, Mol. Cryst. 1, 515 (1966)
• 28. W.T. Coffey, D.S.F. Crothers, Y.P. Kalmykov, J.T. Waldron, Physica A 213, 551 (1995)
• 29. A.V. Ivashenko, V.G. Rumyantsev, Mol. Cryst. Liq. Cryst. 150a, 1 (1987)
• 30. S. Urban, A. Würflinger, B. Gestblom, Phys. Chem. Chem. Phys. 1, 2787 (1999)
• 31. S. Urban, B. Gestblom, W. Kuczyński, S. Pawlus, A. Würflinger, Phys. Chem. Chem. Phys. 5, 924 (2003)

Identifiers

DOI

10.12693/APhysPolA.120.447