An eco-friendly process for the elaboration of poly(ethylene terephthalate) surfaces grafted with biobased network embedding silver nanoparticles with multiple antibacterial modes

This paper reports a strategy for the elaboration of highly performing antibacterial PET surfaces according to an eco-friendly photoinduced process. Modified PET surfaces were elaborated through the grafting of a three dimensional (3D) biopolymer derived from vanillin with antibacterial activity. Biobased polymer grafting was performed through a grafting-from photopolymerization approach initiated from a photoinitiator compound preliminary functionalized onto PET surface. Antibacterial activity of the elaborated materials was tested against Gram-positive (Rhodococcus wratislaviensis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) strains. Antibacterial activity of the biopolymer covalently linked onto PET surface was observed for all tested bacterial strains. Antibacterial effect of vanillin derivative coated onto PET material was combined with a multi-scale roughness induced through the grafting process giving antifouling behaviour to the material. Besides, to improve antibacterial activity of the modified material, biobased network was used as binding sites for photoembedding of antimicrobial silver nanoparticles. The hybrid material showed excellent antibacterial properties against Gram-positive and Gram-negative tested cells. The enhancement of material antibacterial activity against this wide range of pathogens resulted of a combination of different effects: the antibacterial activity of coated vanillin derivative and nanosilver combined with a surface nanostructuration imparting antifouling properties. Grafting of biobased polymer network loaded with nanosilver onto PET material was characterized at various stages of the modification by UV-vis spectroscopy, water contact angle measurements, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface topography was studied by atomic force microscopy (AFM).