STUDY AND APPLICATION ON ELECTROMAGNETIC SHIELDING BASED ON THE BLEND OF COMPOSITES AND CARBON NANOTUBES.

Abstract

Multi walled carbon nanotubes (MWCNT) have filled epoxy and polymer (polymethyl methacrylate, polyurethane) (PMMA, PU) coatings prepared by mechanical grinding with the use of a planetary ball mill. Electromagnetic shielding effectiveness, electromagnetic absorption and reflection properties of the materials have been investigated according to the standard 41 TQSB 71:2004 by a network analyzer (HP E8363B). The experimental results showed that at MWCNT loadings higher than 25 wt. %, epoxy/MWCNT and PMMA, PU coatings have also exhibited the full capability of shielding more than 99% electromagnetic radiation at the 100 MHz-12 GHz frequency range. According to the safety standard of electromagnetic exposure TCVN 3718-1:2005 of Ministry of infomation and communications the allowed values of energy flux density (S) is less than 2 W/m2, so these coating layers will ensure safety for people and equipment working in areas where S is outmarch security level by ten times.