Kok Yeow, You and Z., Abbas and K., Khalid and M. Z. A., Rahman (2010) Improved dielectric model for polyvinyl alcohol-water hydrogel at microwave frequencies. American Journal of Applied Sciences, 7 (2). 270 - 276. ISSN 1546-9239
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, s 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, t, activation energy, Q and entropy change, ?S 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.
|Uncontrolled Keywords:||dielectric constant, loss factor, PVA-water hydrogel, relaxation times|
|Subjects:||T Technology > TK Electrical engineering. Electronics Nuclear engineering|
|Deposited By:||Liza Porijo|
|Deposited On:||28 Jun 2012 00:34|
|Last Modified:||06 Jul 2012 03:42|
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