STRUCTURAL AND ANTIMICROBIAL PERFORMANCE OF POLYVINYL ALCOHOL (PVA) BIOFILMS REINFORCED WITH CuO MICROPARTICLES SYNTHESIZED VIA A SIMPLE CO-PRECIPITATION ROUTE

This study investigates the influence of copper oxide (CuO) microparticles with different morphologies on the structural, mechanical, and antimicrobial properties of polyvinyl alcohol (PVA) biofilms. CuO microparticles were synthesized via a simple co-precipitation method under controlled pH and thermal conditions, yielding fibrous, granular, and spherical morphologies. The particles were physically dispersed into the PVA matrix at different weight ratios using the casting method. The resulting composites were characterized by X-ray diffraction (XRD) with Rietveld refinement, dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical testing, and microbiological assays. The results demonstrate that both particle morphology and concentration significantly affect film crystallinity, Young’s modulus, and tensile strength. Fibrous CuO microparticles enhanced surface antimicrobial activity, producing larger inhibition zones against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, whereas spherical particles exhibited superior bactericidal performance in liquid culture due to improved dispersion and sustained Cu2+ ion release. Despite the absence of particle functionalization, which may have limited interfacial interactions, the composites exhibited promising multifunctional performance. These findings highlight the critical role of particle shape, distribution, and interfacial quality in tailoring the properties of PVA/CuO biofilms.