Macromol Rapid Commun. 2021 Sep 10:e2100473. doi: 10.1002/marc.202100473. Online ahead of print.
ABSTRACT
The combination of complementary, non-covalent interactions is a key principle for the design of multi-stimuli responsive hydrogels. In this work, we report an amphiphilic peptide, supramacromolecular hydrogelator which combines metal-ligand coordination induced gelation and thermoresponsive toughening. Following a modular approach, the incorporation of the triphenylalanine sequence FFF into a structural (C3EG ) and a terpyridine-functionalized (C3Tpy ) C3 -symmetric monomer enables their statistical copolymerization into self-assembled, 1D nanorods in water, as investigated by circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM). In the presence of a bis(terpyridine) functionalized telechelic PEG crosslinker, complex formation upon addition of different transition metal ions (Fe2+ , Zn2+ , Ni2+ ) induces the formation of soft, reversible hydrogels at a solid weight content of 1 wt% as observed by linear shear rheology. The viscoelastic behavior of Fe2+ and Zn2+ crosslinked hydrogels are basically identical, while the most kinetically inert Ni2+ coordinative bond leads to significantly weaker hydrogels, suggesting that the most dynamic rather than the most thermodynamically stable interaction supports the formation of robust and responsive hydrogel materials. This article is protected by copyright. All rights reserved.
PMID:34505725 | DOI:10.1002/marc.202100473
