Alcohol-induced and ion-mediated strategy for flexible polysaccharide-based hydrogels with superior evaporative...

Optimization of physical cross-linking is crucial for developing versatile hydrogels. To meet the demanding requirements of flexible cooling dressings, this work fabricated a biocompatible dual cross-linked hydrogel with superior mechanical strength and sustained cooling performance. A primary physical network from alcohol-induced gelation of tamarind seed polysaccharide (TSP) was enhanced by a secondary ionic network from sodium alginate (SA). The optimal hydrogel exhibited a combination of desirable properties, including tensile stress of 153 kPa, elongation at break of 100.4 %, and a high latent heat of vaporization (~2360.2 J/g), resulting in a maximum temperature difference of 9.62 °C. Prolonged cooling tests on a skin model and meat confirmed its practical effectiveness. These findings demonstrate that the enhanced dual cross-linked network, combining high water-holding capacity, biosafety, and thermal stability, provides a superior and promising material option for flexible physical cooling dressings.