Bilayer Hydrogel With Sustained Release of Clove Essential Oil for Long‐Term Antimicrobial Protection

ABSTRACT With the increasing prevalence of antibiotic‐resistant bacteria, the effectiveness of traditional antibiotics in treating bacterial infections has diminished. To address this challenge, we developed a bilayer hydrogel with sustained antibacterial activity that can efficiently load clove essential oil. The lower layer consists of a polyvinyl alcohol (PVA) hydrogel combined with copper nanosheets (CuNSs), while the upper layer is a mixture of PVA and polyethylene glycol incorporated with essential oil (EO). CuNSs initially exert antibacterial effects by gradually releasing Cu 2+ ions. At the same time, EO provides effective antibacterial action and hydrophobicity, ensuring prolonged bacterial inhibition through slow release. In vitro bacterial inhibition experiments indicated that the bilayer hydrogel maintained 96% antibacterial efficacy even after 72 h. Furthermore, the bilayer hydrogel exhibited superior mechanical strength, solubility, water retention, and thermal stability compared to monolayer hydrogels. These findings suggest that the bilayer hydrogel holds great potential for long‐term infection control applications.