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

American Journal of Applied Sciences

Zulkifly Abbas¹  You K. Yeow¹  Kaida Khalid¹  Mohamad Z.A. Rahman¹ 

关键词: Dielectric constant;    loss factor;    PVA-water hydrogel;    relaxation times;   

DOI  :  10.3844/ajassp.2010.270.276

学科分类：自然科学（综合）

来源: Science Publications

【 摘 要 】

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, ? 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, ?, 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.

【 授权许可】

Unknown