The composite hydrogels of polyvinyl alcohol–gellan gum-Ca2 + with improved network structure and mechanical property

Highlight
• The Ca2 + ion reorganizes the network structure of PVA-GG-Ca2 + hydrogels.
• The Ca2 + ion enhances the mechanical properties of PVA-GG-Ca2 + hydrogels.
• The Ca2 + ion strengthens the electrolytic and hydrogen bonding interactions.

The composite hydrogels of polyvinyl alcohol (PVA) and gellan gum (GG) are of interesting in the biomaterials application. To improve the structure and mechanical property, in this work, Ca2 + ion was introduced to crosslink the polymer chain, and the PVA-GG-Ca2 + hydrogel was formed. By analyzing its structure, mechanical properties, swelling and dehydration kinetics, the effect of molecular interaction on hydrogel structure and properties have been observed. Our result indicates that, as GG is added to hydrogel network, the role of Ca2 + ion is stand out, it reorganizes the network structure, enhances the mechanical properties, and strengthens the electrolytic and hydrogen bonding interactions in PVA-GG-Ca2 + hydrogels. These observations will benefit the development of hydrogels in biomaterials application.