Antibacterial evaluation of polyvinyl alcohol/polyvinyl pyrrolidone/chitosan nanocomposite embedded curcumin@zinc oxide

This study focuses on the fabrication and characterization of PVA/PVP/Cs (Polyvinyl alcohol/Polyvinyl Pyrrolidone/Chitosan) composite membranes embedded with ZnO (zinc oxide) nanoparticles and curcumin as a natural polyphenol with well-known antimicrobial properties. A series of nanocomposite membranes were successfully developed via a solution casting method with varying ZnO loading (2–20 wt%) and fixed 5 wt% curcumin content and physiochemically characterized. Structural and compositional analyses using XRD, FESEM, EDX, and TEM characterizations confirmed the successful incorporation and homogeneous distribution of crystalline ZnO nanoparticles within the amorphous PVA/PVP/Cs polymer matrix. The estimated size of the synthesized ZnO nanoparticles was measured to be around 18–22 nm. TGA thermograms revealed the nanoparticles catalyzed minor reductions in thermal stability while enhancing the residual char at elevated temperatures, a function of their increasing loading fractions. These compositionally tuned PVA/PVP/Cs-ZnO-curcumin nanocomposites exhibited potent antimicrobial efficacy against selected Gram-positive and Gram-negative bacterial strains. The PVA/PVP/Cs-ZnO-curcumin nanocomposites demonstrated tunable antimicrobial activity against bacterial strains, which pave the foundation of eco-friendly, sustainable materials for addressing antimicrobial challenges in biomedical and environmental disinfection applications.