Self-Sorting Double-Network Hydrogels with Tunable Supramolecular Handedness and Mechanical Properties.

Self-sorting, simultaneous, and orthogonal operations during the self-assembly of complex mixtures are commonly observed for biological species but rare in artificial systems. In this study, we designed two gelators (LPF and LPFEG) containing the same chiral phenylalanine core but different achiral peripheral substituents to give hydrogels with opposite supramolecular handedness. When the two hydrogels were mixed, double-network nanofibers with opposite handedness were formed by spontaneous high-order organization and self-sorting of the two gelators. The chiroptical activity of the double-network hydrogels could be tuned by varying the molar ratio of LPF and LPFEG in the mixture, thus showing that the two gelators were highly independent of each other. Enhanced mechanical properties were observed for the interpenetrating networks when the LPF/LPFEG molar ratio was 3:7, with a more than fourfold increase in both the storage (G') and loss modulus (G'') relative to those of the individual hydrogels.