Strengthening gelatin hydrogels using the Hofmeister effect

A simple yet effective soaking treatment has been proposed to fabricate hydrogels with desirable mechanical properties, but the strengthening mechanism of hydrogels lacks an in-depth study. Here, we investigated the influence of kosmotropic citrate anion on the structure and properties of immersed gelatin hydrogels. The obtained hydrogels possessed the properties of high strength, modulus and toughness simultaneously. The dehydration of hydrogels facilitated the interactions among gelatin molecules, resulting in the formation of helix structures. Both the content and length of the triple helices increase with an increase in citrate concentration, which in turn contributes to the strengthening of hydrogels. The excellent mechanical performances of these hydrogels may open up new applications for protein materials.

Automated summary

The influence of kosmotropic citrate anion on gelatin hydrogels was investigated, showing that it can enhance the strength, modulus, and toughness of the hydrogels. Dehydration facilitated interactions among gelatin molecules, leading to the formation of helix structures, while an increase in citrate concentration contributed to the strengthening of the hydrogels by increasing the content and length of triple helices. The excellent mechanical performances of these hydrogels could potentially lead to new applications for protein materials.