Physicochemical and Antibacterial Properties of Synthesized Polyaniline-Chitosan-Nanosilver Hybrid Nanocomposite

Chitosan (Chito) as a biopolymer with high antibacterial, biocompatibility and biodegradability and polyaniline (PANI) as a conductive polymer and silver (Ag) nanoparticles to enhance antibacterial property were used to prepare polyanilin-chitosan-silver (PANI-Chito-Ag) nanocomposites. The synthesis of PANIChito composite and PANI-Chito-Ag nanocomposite was performed through aniline polymerization in the presence of Chito and Ag. In order to evaluate the physicochemical and antibacterial properties of synthesized composite and nanocomposites, several combinations of components with different weight ratios were used. Antibacterial tests were performed using two different types of bacteria: Escherichia coli (gram-negative bacteria) and Staphylococcus aureus (gram-positive bacteria) to determine the antibacterial capability of the PANI-Chito-Ag nanocomposite. The obtained results showed that higher Chito and silver contents produced stronger antibacterial property. The biodegradability test results confirmed that,the biodegradability increased as the content of Chito increased. Also, by increasing Streptomyces (gram-positive bacteria) concentration in natural soil, the biodegradability rate of nanocomposite was enhanced. The results obtained from thermogravimetric analysis (TGA) tests also indicated improvement in thermal stability of PANI-Chito-Ag nanocomposite compared to that of pure Chito. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to analyze and characterize the composition and structure of PANIChito-Ag triple hybrid nanocomposite. The results confirmed uniform distribution of Ag nanoparticles within the polymer matrix.