Research Article Open Access

Improved Dielectric Model for Polyvinyl Alcohol-Water Hydrogel at Microwave Frequencies

You Kok Yeow1, Zulkifly Abbas2, Kaida Khalid2 and Mohamad Zaki Abdul Rahman1
  • 1 , Afganistan
  • 2 ,
American Journal of Applied Sciences
Volume 7 No. 2, 2010, 270-276

DOI: https://doi.org/10.3844/ajassp.2010.270.276

Submitted On: 30 November 2009 Published On: 28 February 2010

How to Cite: Yeow, Y. K., Abbas, Z., Khalid, K. & Rahman, M. Z. A. (2010). Improved Dielectric Model for Polyvinyl Alcohol-Water Hydrogel at Microwave Frequencies. American Journal of Applied Sciences, 7(2), 270-276. https://doi.org/10.3844/ajassp.2010.270.276

Abstract

Problem statement: The study described rigorous dielectric modeling for Polyvinyl Alcohol (PVA)-water hydrogel mixture at microwave frequencies. Approach: A commercial open-ended coaxial sensor was used to measure the dielectric constant, loss factor and ionic conductivity, σ of PVA-water hydrogel mixture ranging concentration of 80-100% water content. Results: The sensor was operating between 0.13 and 20 GHz at and above of room temperature (25±1)°C. Indirectly, the relaxation time, τ, activation energy, Q and entropy change, ΔS of the hydrogel mixtures are determined based on linear fitting of measured data using Debye and Arrhenius approaches. Conclusion/Recommendations: Two main relaxation processes were found ranging 2-10 and 10-20 GHz, respectively. Dielectric dispersion is suggested to describe by combination of Cole-Davidson (CD) and Debye (Dy) processes. The results are discussed qualitatively based on bound states of water in hydrogel mixtures.

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Keywords

  • Dielectric constant
  • loss factor
  • PVA-water hydrogel
  • relaxation times