Antibacterial nanocomposite preparation of polypropylene-Silver using Corona discharge

Silver nanoparticles were coated on polypropylene film to study its antibacterial activity. For this purpose, the surface of polypropylene film was treated by the corona discharge and then the modified polymeric film was immersed in a stable and uniform colloidal solution of silver nanoparticles that was synthesized by chemical reduction of silver salt using hydrazine hydrate. A solution containing the silver nanoparticles were prepared using polyamide resin in three different concentrations of 0.01 M, 0.005 M and 0.001 M. The nanoparticles solution was exposed to ultrasound to prevent their agglomeration. Corona discharge was used to change the polarity of the nonpolar surface of polypropylene and prepare it for coating. The effects of corona treatment conditions on the surface modification and performance of the silver/polypropylene nanocomposite films were investigated. Characterisation of nanoparticles and the coated surface were carried out using UV-vis Spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD) and scanning electron microscope (SEM). The images of SEM suggested that the coating of the film enhances with increasing the power and the time. The antibacterial activity of polypropylene-silver nanocomposite against two types of bacteria including gram-negative Escherichia coli and gram-positive Staphylococcus aureus was measured by disc-diffusion method. The current method of preparation significantly reduces the amount of required nanoparticles which ultimately offers lower production cost.