Toughening elastomers using mussel-inspired iron-catechol complexes

Emmanouela Filippidi; Thomas R Cristiani; Claus D Eisenbach; J Herbert Waite; Jacob N Israelachvili; B Kollbe Ahn; Megan T Valentine

doi:10.1126/science.aao0350

Toughening elastomers using mussel-inspired iron-catechol complexes

Science. 2017 Oct 27;358(6362):502-505. doi: 10.1126/science.aao0350.

Authors

Emmanouela Filippidi^{1

2}, Thomas R Cristiani^{1

3}, Claus D Eisenbach^{1

4}, J Herbert Waite^{1

5}, Jacob N Israelachvili^{1

3

6}, B Kollbe Ahn⁷, Megan T Valentine^{8

2}

Affiliations

¹ Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
² Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA.
³ Materials Department, University of California, Santa Barbara, CA 93106, USA.
⁴ Institut für Polymerchemie, University of Stuttgart, Germany.
⁵ Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
⁶ Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.
⁷ Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
⁸ Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA. valentine@engineering.ucsb.edu.

Abstract

Materials often exhibit a trade-off between stiffness and extensibility; for example, strengthening elastomers by increasing their cross-link density leads to embrittlement and decreased toughness. Inspired by cuticles of marine mussel byssi, we circumvent this inherent trade-off by incorporating sacrificial, reversible iron-catechol cross-links into a dry, loosely cross-linked epoxy network. The iron-containing network exhibits two to three orders of magnitude increases in stiffness, tensile strength, and tensile toughness compared to its iron-free precursor while gaining recoverable hysteretic energy dissipation and maintaining its original extensibility. Compared to previous realizations of this chemistry in hydrogels, the dry nature of the network enables larger property enhancement owing to the cooperative effects of both the increased cross-link density given by the reversible iron-catecholate complexes and the chain-restricting ionomeric nanodomains that they form.

Publication types

Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

Grants and funding

R01 DE018468/DE/NIDCR NIH HHS/United States