Thermal, electrical, optical, and antimicrobial studies of PANI/Ag nanocomposites synthesized by polymerization of aniline on γ-irradiated and PVP-capped Ag colloid

Abstract

A simple and new way was used to modify the thermal, electrical, optical, and antimicrobial properties of conductive polyaniline by embedding a nanosized metallic material in the polymeric matrix. The sequence of fabrication was as follows: first, preparing a silver colloid by gamma-irradiating the precursor and then, aniline monomer was polymerized in the colloid using different molarities of the dopant and the silver itself. The mentioned properties of Ag colloid and the conductive polymer / Ag nanocomposites (NCs) were studied using TGA, electrical measurements, UV-Vis spectroscopy, FTIR, TEM, SEM, DLS, SAED, and EDX. The particle size distribution of the Ag colloid is ranged from 7 to 17 nm. The results showed an increase in the D.C conductivity of NCs thin films with increasing of dopant. All the prepared NCs exhibited medium to high antibacterial activity against Escherichia coli and Staphylococcus aureus reaching the maximum efficiency at PANI: Ag: dopant molar ratio of 1:1:0.83. Also, an electrostatic interaction has been generated between the conductive PANI chains and the free electrons around Ag NPs leading to a conjugating electron cloud in the produced NCs. This electronic behavior facilitates the use of the prepared NCs as supercapacitors, sensors, photocatalysts, or antibacterial materials.