Universiti Teknologi Malaysia Institutional Repository

Improved dielectric model for polyvinyl alcohol-water hydrogel at microwave frequencies

You, Kok Yeow 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

[img] PDF (Abstract)
64Kb

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, 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.

Item Type:Article
Uncontrolled Keywords:dielectric constant, loss factor, PVA-water hydrogel, relaxation times
Subjects:T Technology > TK Electrical engineering. Electronics Nuclear engineering
Divisions:Electrical Engineering
ID Code:26161
Deposited By: Liza Porijo
Deposited On:28 Jun 2012 00:34
Last Modified:24 Aug 2014 09:09

Repository Staff Only: item control page