Physicochemical and antimicrobial characteristics of polypropylene-based nanocomposite containing SiO2-Ag nanoparticles prepared by gamma irradiation

Abstract

This article evaluates the physicochemical and antimicrobial properties when silver-coated silica (SiO2-Ag) nanoparticles as active nanofiller are incorporated into the polypropylene (PP) thermoplastic matrix. The silica (SiO2) nanoparticles were prepared by precipitation method using sodium silicate. After that, silver-coated silica (SiO2-Ag) nanoparticles were synthesized by gamma radiation technique. X-ray diffraction (XRD), Infrared spectroscopy analysis (FTIR) and Transmission electron microscopy (TEM) analysis clarified the formation of SiO2-Ag nanoparticles. SiO2-Ag nanoparticles has a particle size with an average of 70 nm. The melt mixing procedure operated to fabricate PP thermoplastic nanocomposites with various ratios of 1.0, 2.0, and 3.0 part per hundred resin (phr) of the SiO2-Ag nanoparticles. To examine the effect of ionizing radiation on the prepared PP/SiO2-Ag nanocomposites, the samples were exposed to 20 kGy of gamma-irradiation. FTIR, XRD, mechanical analysis, thermogravimetric analysis (TGA), and scanning electron microscope (SEM) were utilized to characterize the physico-chemical alterations of the PP when loaded with SiO2-Ag nanoparticles. It is found that PP/1.0 phr SiO2-Ag nanocomposite revealed superior physico-chemical characteristics than the other two components. The irradiated specimens revealed superior tensile strength (TS) and elastic modulus (EM) over unirradiated ones, whereas inverse effects were predominant in case elongation at break (E%). Tmax of the native PP increased from 335°C to nearly 370°C of PP/1.0 phr SiO2-Ag nanocomposite. It is established that the fabricated PP/SiO2-Ag nanocomposites exhibited potent antimicrobial activity and can be a good candidate for food packaging applications.