Conducting Polymers on Fibres: Applications on Fibres, Microwave Transmission, Complex Permittivity, EMI Shielding Heat Generation and Stability of Microwave Properties
The microwave properties of thin conductive polypyrrole/paratoluene-2-sulfonic acid (PPy/pTSA) films on textiles in the 1-18 GHz frequency range have been investigated.The complex dielectric constant,reflection,transmission and absorption are reported.Changes in these properties over aging times up to 18 months are presented.The permittivity levels for conducting textiles varied with frequency.The real part of permittivity increased with polymerization time and dopant concentration,reaching a plateau beyond certain time-dopant concentration combinations whereas the imaginary part of permittivity exhibited a frequency dependent change throughout the tested range.All conducting textiles had higher values of absorption than reflection.The highest absorption levels were around 50％.The highest transmission loss obtained was around 85％.Results also showed that higher concentrations of the dopant in the polymerization solution and longer reaction times resulted in coatings with better electrical and microwave stability.Both the permittivity and the loss factor were affected by the polymerization time.The reflection contribution to electromagnetic shielding also increased with polymerization time.These materials were also investigated regarding heat generation through microwave absorption,utilizing a thermal camera.A JADE Advanced Thermography Station was used to monitor a range of these composites during simultaneous subjection to microwave radiation,where absorption was observed via heat losses in the material.Samples possessing lower conductivity showed larger amounts of heat loss due to absorption of larger amount of energy compared to that of higher conductivity samples,which were highly reflective and hence has smaller amounts of absorption/heat generation was observed.Heat generation in several conducting polymer samples was detected within swept frequency ranges of 8-9 or 15-16 GHz respectively.The swept frequency ranges were generated by VHP1-130-111 horns with an output power of 30 dB and a 0.5 second sweep time.Emissivity of all samples was estimated to be 0.98.
Polypyrrole Permittivity Aging Electromagnetic Interference Shielding Microwave frequencies
Akif Kaynak Eva H(a)kansson
Centre for Materials and Fiber Innovation,Geelong Technology Precinct,Deakin University,Geelong,Vict School of Engineering and Information Technology,Deakin University,Geelong,Victoria 3217,Australia
国际会议
杭州
英文
2008-10-15（万方平台首次上网日期，不代表论文的发表时间）