Sustainable antibacterial films from cellulose acetate and hydroxyapatite: A green approach to food packaging

Hydroxyapatite (HA), a major mineral component of bones and teeth, has a porous and modifiable structure that contributes to its antibacterial properties. In this study, HA was synthesized from calcium isolated from chicken eggshells via the hydrothermal method and incorporated into a cellulose acetate (CA) matrix to develop biocomposite films for potential food packaging applications. The objectives of this study were to evaluate the antibacterial activity and mechanical performance of CA/HA composites. The films were fabricated with varying HA concentrations (0, 5, 10, 15, and 20 wt%) and characterized for their structural and morphological properties, compressive and tensile strength, thermal stability, and antibacterial activity using the Kirby-Bauer method against both Gram-positive and Gram-negative bacteria. The addition of HA resulted in a reduced pore diameter and enhanced mechanical strength, with the CA/HA (15 %) film exhibiting the highest compressive (0.748 kgf) and tensile (0.397 kgf) strengths. The thermal stability also improved with increasing HA content. Furthermore, antibacterial analysis confirmed that HA incorporation activated the antibacterial function of the CA films. These findings highlight the potential of CA/HA composites as sustainable, antibacterial food packaging materials.