Surface-initiated self-healing of polymers in aqueous media.

Ahn, B. Kollbe; Lee, Dong Woog; Israelachvili, Jacob N.; Waite, J. Herbert

Polymeric materials that intrinsically heal at damage sites under wet or moist conditions are urgently needed for biomedical and environmental applications. Although hydrogels with self-mending properties have been engineered by means of mussel-inspired metal-chelating catechol-functionalized polymer networks, biological self-healing in wet conditions, as occurs in self-assembled holdfast proteins in mussels and other marine organisms, is generally thought to involve more than reversible metal chelates. Here we demonstrate self-mending in metal-free water of synthetic polyacrylate and polymethacrylate materials that are surface-functionalized with mussel-inspired catechols. Wet self-mending of scission in these polymers is initiated and accelerated by hydrogen bonding between interfacial catechol moieties, and consolidated by the recruitment of other non-covalent interactions contributed by subsurface moieties. The repaired and pristine samples show similar mechanical properties, suggesting that the triggering of complete self-healing is enabled underwater by the formation of extensive catechol-mediated interfacial hydrogen bonds.

POLYMERS; MACROMOLECULES; MOLECULAR size; WATER; LIQUIDS

Nature Materials, 2014, Vol 13, Issue 9, p867

1476-1122

Academic Journal

10.1038/nmat4037