Investigation of Antibacterial Properties of Silver Nanoparticles and Polyethylene-Silver Nanocomposites

In the current research, antibacterial properties of silver nanoparticles and polyethylene-silver nanocomposites against Staphyloccocus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria were investigated by using disk diffusion method. For this purpose, silver nanoparticles were synthesized by chemical reduction method and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). No additional peaks were observed in the XRD pattern and the mean particle size of nanoparticles was 21.7 nm. Then, polyethylene-silver nanocomposites containing 5, 10, 20 and 30 weight percent of silver nanoparticles were fabricated by mechanical milling and characterized by XRD, TEM and scanning electron microscopy (SEM). Results showed that the nanoparticles were well dispersed throughout the polyethylene matrix. Antibacterial investigation of samples showed that both nanoparticles and nanocomposites exhibit antibacterial properties against bacteria and this property increases with increasing weight percent of nanoparticles in the disk. Also sliver nanoparticles indicated stronger antibacterial properties against Staphyloccocus aureus than against Escherichia coli.