Electromagnetic Shielding Effectiveness of Polyaniline/Modified-Poly(vinyl Alcohol) Film Composite

Abstract

This work reports the preparation of a conductive composite film, from one of the most conductive polymers, polyaniline (PAn), and a methacryloyl group attached-poly(vinyl alcohol) (M-PVA), in a few straightforward process steps. First, the -OH groups of PVA were modified through trans-esterification reaction using glycidyl methacrylate (GMA), in the presence of N, N, N, N-tetramethylethylenediamine (TEMED) as a catalyst at 60 ℃. After casting the M-PVA into the film in the organic media, the polymerization of aniline was performed onto this surface using APS as an oxidant in 1.0 M HCl. The effects of conditions, including the concentrations of M-PVA used for film-casting, and aniline, were investigated on PAn content (%) and conductivity. It was observed that the conductivity of the thin and almost transparent composite films (containing 17.5% of PAn) reached to 10-4 Scm-1. The characterization of the samples was conducted by ATR-FTIR, contact angle-wetting time measurements, and SEM-EDX techniques. The usability of the conductive composite film in the electromagnetic interference (EMI) shielding was examined within 30 MHz-3 GHz, through the measurement of electromagnetic interference shielding effectiveness (EMSE) and relative shielding efficiency values of absorption (Ab) and reflection (Re). Twice PAn deposited-composite film showed an average 5.6 dB EMSE value that corresponds to 71% of shielding through the Ab mechanism, dominantly.