Self-healing gelatin ionogels.

We demonstrate room temperature (20°C) self-healing, and substantial recovery (68-96%) of gel rigidity of gelatin, a polypeptide, ionogels (made in 1-ethyl-3-methylimidazolium chloride ionic liquid (IL) solutions via thermal treatment, IL≤5% (w/v)) after they were cut using a surgical blade. The recovery process did not require any stimuli, and the complete healing under ambient condition required about 10h.The self-healing owed its origin to the reformation of network structures via imidazolium ion mediated charge quenching of deprotonated residues, and hydrophobic interaction between neighbouring alkyl tails of IL molecules. The rate of healing determined from the growth of rigidity modulus was 20±5 mPa/s independent of ionic liquid content of the gel. This was true regardless of the fact that ionogels containing more IL had a lower gel modulus due to propensity of hydrophobic linkages, but these were agile enough to recover their network structures to a higher degree during the healing process. These features indicate that the gelatin ionogel being biocompatibile, and biodegradable holds great potential for applications in the field of biomedical engineering.