In situ synthesis of silver nanoparticles on modified poly(ethylene terephthalate) fibers by grafting for obtaining versatile antimicrobial materials

Because of having high mechanical properties and cheapness of PET textiles, functionalization of them for new properties is an active research area. In the present work, methacrylic acid (MAA)-grafted PET fibers (PET-g-MAA) were obtained by grafting of MAA monomers to PET surface for an antimicrobial material synthesis. The morphologies of the obtained graft copolymers were examined with a scanning electron microscopy (SEM), and the chemical modification after grafting was determined with Fourier-transform infrared spectroscopy (FTIR) analysis. Subsequently, silver ions were adsorbed onto the PET-g-MAA fibers surface and the adsorbed ions to the surface were reduced to silver nanoparticles (AgNPs) by UVC light. The morphology of fiber surfaces modified with MAA and coated with AgNPs was examined by SEM studies, and it was observed that AgNPs were disturbed along the fibers. The presence of silver on the surface was also confirmed by energy-dispersive X-ray spectroscopy (EDS) and energy dispersion X-ray fluorescence spectrometry (EDXRF). The crystalline structure of the original PET fiber, PET-g-MAA fiber and PET-g-MAA fiber modified with AgNPs was investigated by X-ray diffraction (XRD). The thermal properties of the obtained fibers were investigated by thermogravimetric analysis (TGA). The immobilization of AgNPs on the grafted fibers leads to a change on the patterns of TGA curves. The most significant change is the less weight reduction in the temperature range of 200-300 degrees C. Disk diffusion test was performed using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25,922) bacteria in order to investigate the antibacterial ability of the obtained fibers, and it was found that the fibers coated with AgNPs had antibacterial effect on both bacterial species. The cytotoxicity of the groups with the best antibacterial properties was determined by MTT test, and the synthesized material did not have cytotoxic effects on L929 fibroblast cells. The material obtained has the potential to be used in antimicrobial applications.