Dilution-induced gel-sol-gel-sol transitions by competitive supramolecular pathways in water

Fascinating properties are displayed by synthetic multicomponent supramolecular systems that comprise a manifold of competitive interactions, thereby mimicking natural processes. We present the integration of two reentrant phase transitions based on an unexpected dilution-induced assembly process using supramolecular polymers and surfactants. The co-assembly of the water-soluble benzene-1,3, 5-tricarboxamide (BTA-EG(4)) and a surfactant at a specific ratio yielded small-sized aggregates. These interactions were modeled using the competition between self-sorting and co-assembly of both components. The small-sized aggregates were transformed into supramolecular polymer networks by a twofold dilution in water without changing their ratio. Kinetic experiments show the in situ growth of micrometer-long fibers in the dilution process. We were able to create systems that undergo fully reversible hydrogel-solution-hydrogel-solution transitions upon dilution by introducing another orthogonal interaction.

Automated summary

Synthetic multicomponent supramolecular systems exhibit fascinating properties through competitive interactions. This study presents the integration of two reversible phase transitions based on dilution-induced assembly process. Small-sized aggregates were formed by the co-assembly of water-soluble benzene-1,3,5-tricarboxamide and a surfactant, which were transformed into supramolecular polymer networks by dilution. Additionally, the introduction of orthogonal interaction allowed for fully reversible hydrogel-solution-hydrogel-solution transitions.