Hybridization as a promising approach to engineering the desired performance of bio-nanocomposites: GO-ZnO hybrid reinforced PCL.

This study investigates the impact of hybridizing graphene oxide (GO) with zinc oxide (ZnO) at varying ratios (1:1 and 1:2) and concentrations (0.5, 0.75, 1 wt%) on the rheological, mechanical, hydrolytic degradation, and antibacterial properties of polycaprolactone (PCL) nanocomposites. GO, ZnO, and GO-ZnO nanohybrids were synthesized and characterized using TEM, AFM, Raman, and FT-IR spectroscopy to confirm their structure and composition. PCL/ZnO nanocomposites were fabricated via solution mixing. Mechanical testing revealed that 0.5 wt% GO-ZnO (1:1) significantly enhanced tensile strength, Young's modulus, and elongation at break, owing to strong interfacial adhesion and uniform dispersion within the PCL matrix. Rheological analysis indicated increased elasticity at 1 wt%, suggesting agglomeration and altered hydrodynamic interactions, while viscosity decreased, particularly at 0.75 wt%, due to sliding effects and accelerated thermal degradation. Hydrolytic degradation tests demonstrated that 0.75 wt% GO-ZnO composites lost 70.2% weight after 26 days in PBS, compared to negligible loss in pure PCL. Antibacterial activity improved by 50% with 0.5 wt% GO-ZnO incorporation. These results underscore PCL/GO-ZnO nanocomposites' enhanced mechanical strength, rapid degradation, and antibacterial efficacy, positioning them as promising candidates for bio-packaging applications.