Investigation into the structural design of polyethylene glycol-based hydrogels and their application in human thermal management

This study reports the fabrication of a dual-network phase-change hydrogel composed of polyethylene glycol (PEG), gelatin (Gel), and oxidized carboxymethyl cellulose (OCMC). The primary network is formed via a dynamic Schiff base reaction between OCMC and Gel, whereas the secondary network is constructed through multiple hydrogen-bonding interactions among PEG, Gel, and OCMC. This dual-crosslinked architecture markedly enhances the mechanical strength and thermal stability of the material. The resultant hydrogel exhibits robust adhesive performance, which facilitates its practical application. The hydrogel possesses a phase-change enthalpy of 108.94 J/g and a thermal conductivity of 0.50 W/(m·K), thus enabling efficient thermal regulation. Preliminary human trials demonstrate a sustained and significant localized cooling effect. Additionally, the material displays favorable mechanical properties, low leakage rates, and excellent cyclic stability. These characteristics stem from the synergistic interactions between the covalent and hydrogen-bonded networks, which construct a stable microenvironment for PEG and endow it with highly reversible crystallization–melting behavior. In summary, the hydrogel developed in this work exhibits considerable potential for applications in thermal energy storage, smart textiles, and biomedical dressings.