Freeze-Thaw-Induced Physically Cross-Linked Poly(Vinyl Alcohol)/Alginate Hydrogels Incorporating Silver-Doped Zinc Oxide and Clove Oil.

This study reports the fabrication and comprehensive characterization of multicomponent silver-doped zinc oxide (Ag/ZnO)-poly(vinyl alcohol)/alginate(PVA/Alg) biocomposite hydrogels enriched with clove oil (CO), prepared via a scalable and solvent-free freeze-thaw (F-T) process. The F-T treatment generated physically cross-linked hydrogel networks with preserved structural integrity and favorable mechanical performance. Morphological analysis revealed a homogeneous and interconnected porous architecture at low CO contents, while contact-angle measurements confirmed hydrophilic surfaces with composition-dependent wettability. X-ray diffraction and Fourier transform infrared spectroscopy verified the successful incorporation of Ag/ZnO and CO into the PVA/Alg matrix without disrupting the overall polymer network. Barrier performance was strongly governed by CO content. Increasing CO loading reduced water vapor transmission through the formation of hydrophobic domains, while oxygen permeability reached a maximum at 1 wt.% CO, highlighting tunable mass transport behavior. The hydrogels exhibited rapid swelling, sustained hydration stability for up to 72 h, and a composition-dependent CO release behavior. Collectively, these findings elucidate clear structure-processing-property relationships in Ag/ZnO-incorporated PVA/Alg hydrogels containing CO and demonstrate their promise as multifunctional materials for further investigation in wound dressing applications.