Development of Polymer‐Enhanced Bentonite Composites: A Dual‐Functional Material for Sustained Zinc and Phosphate Delivery With Antibacterial, Antifungal, and Antioxidant Applications

ABSTRACT Zinc‐ and phosphate‐doped bentonite composites (Zn–P–Bento) and polymer‐modified variants (Zn–P–Bento–Starch) and (Zn–P–Bento–Cellulose) were synthesized using a simple aqueous‐phase method and comprehensively characterized by UV‐Visible spectroscopy, FT‐IR, X‐ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive x‐ray spectroscopy (EDS) to investigate their structural, thermal, and morphological properties following doping. The novelty lies in the dual doping of bentonite clay with zinc and phosphate, as well as the inclusion of organic binders such as starch and cellulose, to test various biomedical applications. Antimicrobial activity of the synthesized composites was evaluated against Escherichia coli , Staphylococcus aureus , and Candida albicans via the agar well diffusion method, where all the composites exhibited clear inhibition zones with diameters ranging from 11 to 14 mm (bacteria) and 17 to 19 mm (fungi). Antioxidant activity, measured by DPPH assay, revealed the radical scavenging capacity of composites between 45% and 53%. The composites lead to sustained release of zinc (9%–12%) and phosphate (10%–13%) over 7 days in water. Compared to previously reported clay‐based materials, the prepared composites demonstrated enhanced antimicrobial, antioxidant, and controlled release behavior.