Title: Composition and Structure of Oyster Adhesive Reveals Heterogeneous Materials Properties in a Biological Composite

Abstract

Oyster reefs help maintain coastal ecosystems by filtering water, holding silt in place, and absorbing storm surge energy. We are just beginning to understand the chemical and structural nature of the adhesive used by these animals for building such reef communities. The adhesive has a high calcium carbonate content relative to other bioadhesives, but also appreciable levels of organics, presumably for bonding. The studies presented here use X‐ray absorption near edge structure spectroscopy, X‐ray photoemission electron microscopy, scanning electron microscopy, and microhardness methods to understand the composition, as well as the mechanical properties, of this biological material. Oyster adhesive appears to be a heterogeneous mixture of calcium carbonate and silica inclusions arranged randomly within a matrix that lacks any observable structure. Microindentation shows inclusions are significantly harder than their surroundings. This hard plus soft strategy has been noted in other biological materials, although not in any adhesives. These compositional and structural insights help propose a mechanism by which the animals generate their adhesive. Such an intriguing structure, along with resulting mechanical implications, may help explain how oyster reefs can thrive despite being subjected to demanding forces created by predators and the environment around them.

Authors:

Metzler, Rebecca A. ^[1]; Rist, Rebecca ^[1]; Alberts, Erik ^[2]; Kenny, Paul ^[3]; Wilker, Jonathan J. ^[4]

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+ Show Author Affiliations

1. Department of Physics and Astronomy Colgate University 13 Oak Dr. Hamilton NY 13346 USA
2. Department of Chemistry Purdue University 560 Oval Drive West Lafayette IN 47907 USA
3. Baruch Marine Field Lab University of South Carolina P.O. Box 1630 Georgetown SC 29442 USA
4. Department of Chemistry and School of Materials Engineering Purdue University 560 Oval Drive West Lafayette IN 47907 USA

Publication Date:

Tue Aug 16 00:00:00 EDT 2016

Sponsoring Org.:

USDOE

OSTI Identifier:

1401005

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Advanced Functional Materials

Additional Journal Information:

Journal Name: Advanced Functional Materials Journal Volume: 26 Journal Issue: 37; Journal ID: ISSN 1616-301X

Publisher:

Wiley Blackwell (John Wiley & Sons)

Country of Publication:

Germany

Language:

English