Synthesis, characterization and application of double network hydrogels with superior ultraviolet resistance and antioxidant properties constructed from oligomeric proanthocyanidins and poly(vinyl alcohol)/sodium alginate

Abstract

Abstract A structurally dense hydrogel, with strong hydrogen bonding networks, was formed from poly(vinyl alcohol), sodium alginate, and oligomeric proanthocyanidins, using a combination of freeze-thaw cycles and calcium ion cross-linking. The structure of the hydrogel was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Mechanical testing and thermogravimetric analysis showed that incorporation of proanthocyanidins enhanced both the mechanical properties and the thermal stability of the hydrogel. The hydrogel was also demonstrated to have excellent ultraviolet resistance and antioxidant properties. The hydrogel was further shown to produce an electrochemical response, strongly suggesting that such hydrogels could be used as an electronic skin, with exciting potential in medical and other fields.