Thermally irreversible supramolecular hydrogels record thermal history

A low-molecular-weight gelator produces a supramolecular hydrogel, which shows thermoreversible gel-sol transition. Here, we first report a thermo-irreversible hydrogel constructed from a novel low-molecular -weight gelator using dynamic covalent chemistry and its application to thermal history recording. The low -molecular-weight gelator, which was composed of a peptide, an alkyl chain and an aromatic ring, was synthe-sized via the Schiff base formation using a volatile aromatic aldehyde and an amine-terminated peptide amphiphile. The prepared hydrogel underwent gel-to-sol transition upon heating, which was similar to other reported supramolecular hydrogels. Interestingly, the resultant sol did not return to the gel state upon cooling under designed conditions, indicative of a thermo-irreversible hydrogel. We also demonstrated that thermo-irreversible hydrogels record thermal history without requiring electrical power for applications in logistics.

Automated summary

A thermo-irreversible hydrogel was constructed using dynamic covalent chemistry and a low-molecular-weight gelator, which consisted of a peptide, an alkyl chain, and an aromatic ring. The hydrogel exhibited a gel-to-sol transition upon heating but did not revert back to the gel state upon cooling, indicating its thermo-irreversibility. The hydrogel was also demonstrated to record thermal history without the need for electrical power in logistics applications.