Selective Adsorption of Supramolecular Poly(vinyl alcohol)–Hyaluronic Acid−β-Cyclodextrin Hydrogels for Environmental Applications

Supramolecular hydrogels have attracted considerable interest for agricultural and environmental applications due to their biocompatible and nontoxic properties. In this work, a poly(vinyl alcohol)–hyaluronic acid−β-cyclodextrin (PVA–HA–bCD) supramolecular hydrogel cross-linked with epichlorohydrin was prepared via a one-pot synthesis using different PVA–HA weight ratios (10–1 to 10–5 w/w) and compared with PVA–HA hydrogels without bCD. The structure, surface, morphology, and mechanical properties of the hydrogels were investigated using FT-IR, SEM, and rheological measurements. Hydrogels containing bCD exhibited larger pore sizes and higher gel–sol transition points. The PVA–HA hydrogel with a ratio of 10–3, both with and without bCD, showed the highest swelling ratio. Interestingly, these supramolecular hydrogels demonstrated enhanced loading efficiency and sustained release behavior of limonene, a highly volatile compound. Moreover, the developed supramolecular hydrogels exhibited selective adsorption toward the cationic dye methylene blue (MB). Overall, this study demonstrates the potential of PVA–HA–bCD supramolecular hydrogels as effective biosorbents for agricultural applications.