Enhancing the multifunctional properties of polycaprolactone/chitosan films with zirconium dioxide nanoparticles for biomedical and flexible optoelectronic applications.

This study addresses the growing need for sustainable and multifunctional materials by developing novel polycaprolactone (PCL)/chitosan (CS)/zirconium dioxide (ZrO) nanocomposite films. While PCL and CS offer biocompatibility and biodegradability, their combined use presents limitations for advanced applications requiring specific functional features. The incorporation of ZrO nanoparticles aims to overcome these limitations and create materials with enhanced mechanical, electrical, optical, and antibacterial properties. The nanocomposites were synthesized a simple casting method, and their properties were comprehensively characterized. Results show that the addition of ZrO significantly improves the mechanical, electrical, optical, and antibacterial characteristics of the PCL-CS copolymer. Specifically, a 2 wt% ZrO concentration yielded an optimal balance of mechanical strength, stiffness, ductility, and toughness, with a 63% increase in ultimate tensile strength and a 93% increase in toughness compared to neat PCL-CS. The electrical conductivity was significantly enhanced with increasing ZrO content and temperature, and the dielectric properties were improved, positioning ZrO as a mid-range dielectric filler. Optical analysis revealed that ZrO content tunes the absorbance, energy gap, and refractive index, making these films suitable for optical applications. Furthermore, the nanocomposites exhibited remarkable antibacterial activity against both Gram-positive and Gram-negative , with inhibition zones increasing with ZrO concentration, demonstrating the synergistic effect between chitosan and ZrO. These findings highlight the potential of PCL-CS/ZrO nanocomposite films as versatile and sustainable alternatives for a wide range of applications, including biomedical devices, flexible optoelectronics, and smart packaging.