Electrochemical synthesis of polyaniline on activated carbon surface and its electromagnetic properties

Abstract

In order to improve the electromagnetic properties of single polyaniline (PANI), polyaniline/activated carbon (PANI/AC) composites were prepared on the surface of an activated carbon-pencil core electrode (AC-PEC) by cyclic voltammetry of electrochemical synthetic method. The preparation conditions were optimized using charge of composite material, such as scanning potential range, scanning rate, aniline concentration, supporting electrolyte concentration, number of scanning cycles, applied neutral electrolyte concentration, concentration of activated carbon dispersion and effective conduction length of AC-PEC. The optimized results show that the as-prepared PANI/AC has the highest charge and the best stability when AC-PEC with 1.5 cm effective length (75mg/mL activated carbon dispersing liquid concentration) is put in a mixture solution (pH=0.22) containing 0.3 mol/L H₂SO₄, 0.2 mol/L KCl and 0.2 mol/L aniline (An) at the scanning speed of 0.04 V/s in a potential range from -0.4 V to 1.1 V with 8 cycles scanning successively. PANI/AC exhibits a kind of core-shell structure with good conductivity, and its impedance is lower than those of PANI and AC. It can absorb electromagnetic wave of 7.44-15.12 GHz in varying degrees, which is wider than that of pure PANI in the range from 10.48 GHz to 14.32 GHz.