Bergenin‐Enhanced PEG‐PVA Hydrogel for Efficient Adsorption of Rose Bengal Dye

Abstract This study explores the formation of an advanced hydrogel by incorporating Bergenin (BER), a hydrophobic polyphenol obtained from Bergenia stracheyi , into a polyvinyl alcohol (PVA) matrix as a cross‐linking agent. The inherent low aqueous solubility of BER was overcome by utilizing a biocompatible and eco‐friendly solvent, polyethylene glycol 400 (PEG 400), that dissolves BER with a mole fraction solubility of 4.15 × 10 −2 at 318.15 K, enabling its integration into the PVA matrix and enhancing hydrogel properties. The resulting PVA/PEG/BER hydrogel demonstrated superior mechanical strength, thermal stability, and viscoelastic performance compared to the PVA/PEG hydrogel. It exhibited a zero‐shear viscosity of 87,000 Pa.s (PVA/PEG: 27,800 Pa.s), a storage modulus of 2,300 Pa (PVA/PEG: 1,760 Pa), swelling capacity of 340% (PVA/PEG: 260%), and an exceptional Rose Bengal dye adsorption capacity of 666.6 mg/g (PVA/PEG: 248.7 mg/g). Adsorption kinetic analysis followed a pseudo‐second‐order model ( R 2 = 0.992), and the Freundlich isotherm ( R 2 = 0.977) indicated heterogeneous, multilayer adsorption. This approach affirms the success in developing robust hydrogels cross‐linked with hydrophobic polyphenols with significant potential for environmental and industrial applications.