Synthesis and characterization of polyaniline/silver nanocompozites and preparation of conductive antimicrobial films

In this study silver nanoparticles, existing as metallic nanoparticles, holding an important place in nanotechnology and having antibacterial properties were synthesized and various characteristic properties were investigated. Subsequently the inherently conductive polyaniline was synthesized by using an optimized process to prepare polyaniline/silver (PANI/Ag) nanocomposites via in-situ polymerization. PANI and PANI/Ag nanocomposite films were produced by the drop-by-drop method. The electrical conductivities of HCl doped PANI film and PANI/Ag nanocomposite films were measured according to the standard four-point-probe technique. The nanocomposite films exhibited an increase in electrical conductivity compared to neat PANI. The increase of conductivity of PANI/Ag nanocomposites may be partially due to the doping or complex formation effect of Ag. PANI and PANI/Ag nanocomposites were characterized by spectroscopic methods, including UV-Vis, FT-IR and PL. UV-Vis and FT-IR results showed that Ag nanoparticles affect the quinoid units along the polymer chain and indicate strong interactions between Ag nanoparticles and quinoidal sites of PANI. PL properties of PANI and PANI/Ag nanocomposites were studied and the photoluminescence intensity of PANI/Ag nanocomposites was higher than that of neat PANI. The amount of weight loss and thermostability of PANI and PANI/Ag nanocomposites were determined by TGA. The morphology of nanoparticles and films were examined by SEM. SEM analyses revealed that Ag nanoparticles were well dispersed and isolated in nanocomposite films, but some agglomerates were detected in some regions of the nanocomposite films. The existence and distributions of Ag nanoparticles in PANI film matrix were analyzed by EDX. Finally, the syntheses of new conducting antimicrobial nanocomposites and production of their films, may have potential applications in industry and health oriented areas. The antimicrobial properties of the nanocomposite films obtained were also examined.