Surface-initiated self-healing of polymers in aqueous media

• Published in: Nature materials Vol. 13; no. 9; pp. 867 - 872
• Main Authors: Ahn, B Kollbe, Lee, Dong Woog, Israelachvili, Jacob N, Waite, J Herbert
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.09.2014
• Subjects: Acrylic Resins - chemistry; Aqueous solutions; Biomimetic Materials - chemistry; Catechols - chemistry; Chemical synthesis; Polymers; Polymethacrylic Acids - chemistry; Surface Properties; Water - chemistry
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat4037

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.