Cover Image

Microwave dielectric properties of binary solvent wateralcohol, alcohol-alcohol mixtures at temperatures between -35°C and +35°C and dielectric relaxation studies

Adel Megriche, Abdellatif Belhadj, Arbi Mgaidi

Abstract


In this work, our objective was to study the complex permittivity of binary mixtures of water-ethanol, water-methanol and methanol-ethanol with various mole fractions at temperature between -35 and 35 °C.
Measurements were made in the frequency domain from 300 kHz to 1.3 GHz by means of an open ended coaxial line technique coupled to a network analyzer. Water-ethanol and water-methanol mixtures display a Kraszewski Law while methanol-ethanol mixture shows a Shivola-Kong Law. The static dielectric constant, εs were obtained from the plateau of ε'(ω) curve, in water rich mixture or alcohol rich mixture has similar real permittivity ε' of pure liquids. The values of εs mixtures increase by decreasing the temperature assigned to the cooperative dynamics H-bond system in mediums. The validity of permittivity measurements according to the temperature are verified by the Queen-King Law and the j (0ï‚£ jï‚£2) A constants are compared with literature data. The dielectric relaxation behaviour of water-ethanol mixture can be better described with a Cole-Davidson function while for methanol-ethanol one, a Debye function gives a good fit. At 25 °C, the relaxation time ï´ in the aqueous mixtures of ethanol and methanol sharply increased with increasing alcohol concentration.

Full Text:

PDF

References


- D. Bertolini, M. Cassetari, G. Salvetti, “Dielectric and thermodynamic properties of CHF3 near the critical temperature», J. of Molecular Liquids.1984, 28, 175-189.

- H. Aghaie, M. Aghaie, J. Sci. Univ. Teach. Ed.,Iran, 1993, vol. 5, (No.1,2), 25.

- R.L. Smith Jr., S.B. Lee, H. Komori, K. Arai; “Relative permittivity and dielectric relaxation in aqueous alcohol solutionsâ€, Fluid Phase Equilibria , 1998,144, 315-322.

- H. Yilmaz “ Excess properties of Alcohol-water systems at 298.15Kâ€, Turk J. Phys. 2002, 26, 234-246.

- D.Bertolini, M. Cassetari, G. Salvetti, E. Tombari and S.Veronesi “The Dielectric relaxation of water- alcohol and alcohol-alcohol solutionsâ€. Journal of Non-Crystalline Solids 1991, 131-133, 1169-1173.

- J. Z. Bao, , C.C. Davis, M. L. Swicord, Microwave dielectric measurements of erythrocyte suspensions, Biophysical Journal, 1994, Volume 66, 2173-2180.

- T. Sato, R. Buchner, Cooperative and molecular dynamics of alcohol/water mixtures: the view of dielectric spectroscopy. Journal of Molecular Liquids, 2005, 117, 23-31.

- Y. S. Joshi, P. G. Hudge, A. C. Kumbharkhane, S. C. Mehrotra, Journal of Molecular Liquids 2011, 169, 70-76.

- S. Sudo N. Shinyasiki, Y. Kitsuki, S. Yagihara, J.Phys. Chem. A. Dielectric relaxation time and relaxation time distribution of alcohol-water mixtures. 2002, 106, 458-464.

-H.H. Lowry, The significance of the dielectric constant of mixture. Journal of the Franklin Institute, March 1927, Volume 203, Issue 3,Pages 413-439

- Yanhong Liu, Juming Tang, Zhihuai Mao, Analysis of bread dielectric properties using mixture equations. Journal of Food Engineering, 2009, Volume 93, Issue1, Pages 72-79.

- S. Nagy, I. Szalai, Nonlinear dielectric effect of dipolar fluid mixtures. Journal of Molecular Liquids. 2011,164, 157-161.

- R.J. Sengwa, V. Khatri. Study of static permittivity and hydrogen bobded structures in amide-alcohol mixed solvents. Thermochimica Acta, 2010,Volume 506, Issues1-2, 10, Pages 47-51.

- A. Jouyban, S. Soltanpour, H. K. Chan, A simple relationship between dielectrictric constant of mixed solvent composition and temperature. International Journal of Pharmaceutics, January 2004, Volume 269, Issue 2, 28, Pages 353-360.

- Z. Chen, K. Z. Zhao, Dielectric relaxation spectroscopy of macroporous IER beads suspensions dispersed in primary alcohols and water-ethanol mixtures. Colloids and Surfaces A: Physicochem. Eng. Aspects. 2007,V 292, Issue 1-5, 42-50.

- S. Mashimo, S. Kuwabara, S. Yagigara, K. Higasi, The dielectric relaxation of mixture of water and primary alcohol, J. Phys. Chem. 1989, 90 (6), 3292-3294.

- M.A. Stuchly and S.S. Stuchly, IEEE Trans Instrum. Meas. 1980, vol IM-29, 176-183.

- N. Bohli, A. Belhadj Mohamed, V. Vigneras-Lefebvre and J.-L. Miane, Eur. Phys. J. Appl. Phys., Dielectric and rheological properties of polyaniline organic dispersions, 2009,46, 20405.

- J. R. Mosig, J.C.E. Besson, M. Gex-Fabry and F.E. Gardiol, Reflection of an open-ended coaxial line and application to non destructive measurements materials, IEEE Trans Instrum. Meas. 1981, vol IM-30, pp 46-51,




DOI: http://dx.doi.org/10.13171/mjc.1.4.2012.20.02.15

Copyright (c) 2015 Mediterranean Journal of Chemistry