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Abstract:
In this work, we developed and characterized the membranes based on polyvinyl chloride plastisol modified with silver nanoparticles deposited on silica. The aim of the study was to obtain a functional PVC plastisol composite for use as linings and protective coatings, with improved mechanical, thermal, and antimicrobial properties. The plastisol was prepared by mixing PVC resin with a plasticizer (bis(2-ethylhexyl) adipate). Silver nanoparticles were produced by two methods: chemical reduction using sodium citrate and gum arabic, and these particles were deposited on Aerosil®200 silica. These composites were introduced into plastisol at different concentrations and then processed into films by gelation and hydraulic pressing. The formation of silver nanoparticles was confirmed by UV-Vis spec-trophotometry, and the morphology of the composites was examined by scanning electron microscopy. Further char-acterization of the materials included infrared spectroscopy, thermomechanical analysis, mechanical property testing, and thermogravimetric analysis. Mechanical properties such as Young’s modulus, tensile strength, and elongation at break were determined by static tensile tests. Shore hardness tests were also performed to evaluate the stiffness of the composites. The antimicrobial activity of the membranes was evaluated according to ASTM method E2149-01 using reference strains of S. aureus and E. coli. Studies have shown that silver nanoparticles effectively inhibited the growth of E. coli, especially at higher concentrations of AgNPs, while they had no effect on S. aureus. AgNPs modi-fied membranes obtained from the reduction of AgNO₃ with sodium citrate and deposited on silica showed higher microbiological activity than those with AgNPs reduced with gum arabic. An optimal filler content in the range of 1 to 1.5% provides the most favorable combination of mechanical, thermal, and antibacterial properties.

Keywords:
plastisol, silver nanoparticles