Electromagnetic shielding effectiveness of high loft activated carbon web prepared by using acrylic waste

Abstract

This work represents a novel method for the formation of activated carbon web using charcoal through physical activation in high temperature muffle furnace. The acrylic fibrous waste was separated from bath mats and transferred to carding machine which was transferred to needle punching machine for obtaining a compact structure of non-woven. The acrylic web was first stabilized at 250 °C with a heating rate of 50 °Chr-1. The stabilized web was again raised to high temperature (700 °C, 900 °C and 1100 °C) using charcoal for single stage carbonization and activation. The impact of temperatures on the characteristics of carbon webs was analyzed in terms of yield, dusting, flexibility, XRD (x-ray diffraction analysis) and EDX (energy dispersive x-ray analysis). The EM (electromagnetic) shielding of prepared webs was analyzed by using wave guide method which measures shielding effectiveness at 2.45 GHz (high frequency region). It was found that shielding effectiveness increased from 2.21 dB to 23.71 dB as the carbonization temperature was increased from 700 °C to 1100 °C. Not only the carbonization temperature but the impact of thickness of carbon webs on shielding effectiveness was also observed. The shielding effectiveness increased when the thickness of carbon webs increased because of internal reflections and more absorption of electro-magnetic radiations.