Conducting polyaniline composites as microwave absorbers

Abstract

Conducting polymers are excellent microwave absorbers and they show technological advantage when compared with inorganic electromagnetic absorbing materials, being light weight , easily processable , and the ability of changing the electromagnetic properties with nature and amount of dopants , synthesis conditions, etc. In this paper we report the synthesis , dielectric properties, and expected application of conducting composites based on polyaniline (PAN). Cyclohexanone soluble conducting PAN composites of microwave conductivity 12.5 S/m was synthesized by the in situ polymerization of aniline in the presence of emulsion grade polyvinyl chloride. The dielectric properties of the composites , especially the dielectric loss, conductivity , dielectric heating coefficient , absorption coefficient , and penetration depth, were studied using a HP8510 vector network analyzer. The microwave absorption of the composites were studied at different frequency bands i.e, S, C, and X bands (2-12 GHz). The absorption coefficient was found to be higher than 200 m -' and it can be used for making microwave absorbers in space applications . POLYM . COMPOS., 28:588-592 , 2007.

Studying the electrical, thermal, and photocatalytic activity of nanocomposite of polypyrrole with the photoadduct of K3[Fe(CN)6] and diethylenetriamine

“…Conducting polymers have attracted a considerable attention from all polymer branches owing to their interesting technological applications such as energy storage devices, sensors, and strong EMI materials 1 …”

Complex permittivity and conductivity of poly(p-phenylenediazomethine) and its blends at microwave frequencies

“…They have widespread applications in rechargeable batteries, electrochromic devices, gas separation membranes, and above all as a strong EMI shielding materials (Diaz et al , 1981Peres and Depaoli 1992;Bhat and Yasmin 1995;Pellegrino et al 1996;Kizilyar et al 1999). All dielectric materials are characterized by their dielectric parameters such as dielectric constant, conductivity and dielectric loss factor (Honey John et al 2007b). These parameters differ with frequency, temperature, pressure, etc.…”

Magnetic metal nanoparticles coated polyacrylonitrile textiles as microwave absorber

“…The intensive usage of Electromagnetic wave in such areas causes electromagnetic interference (EMI) and electromagnetic compatibility (EMC) problems [1]. To overcome these problems metallic shields [1,2], ferrite absorbers [3][4][5][6][7][8][9][10][11], ferroelectric materials [12][13][14], composite materials [15,16], and conductive polymers [17][18][19][20][21][22][23] are used. Metal nanoparticles on polymer structure is not forming a metallic infinite layer, reflecting all EM, and the damping of it via interparticle reflections on the surface makes nano-metals as proper candidate material for shielding and absorbing.…”