Organic interlamellar layers, mesolayers and mineral nanobridges: contribution to strength in abalone (Haliotis rufescence) nacre

Maria I Lopez; Pedro E Meza Martinez; Marc A Meyers

doi:10.1016/j.actbio.2013.12.016

Organic interlamellar layers, mesolayers and mineral nanobridges: contribution to strength in abalone (Haliotis rufescence) nacre

Acta Biomater. 2014 May;10(5):2056-64. doi: 10.1016/j.actbio.2013.12.016. Epub 2013 Dec 15.

Authors

Maria I Lopez¹, Pedro E Meza Martinez², Marc A Meyers³

Affiliations

¹ Materials Science and Engineering Program, University of California, San Diego, La Jolla, USA. Electronic address: mil032@ucsd.edu.
² Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, USA.
³ Materials Science and Engineering Program, University of California, San Diego, La Jolla, USA; Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, USA; Department of Nanoengineering, University of California, San Diego, La Jolla, USA.

PMID: 24345555
DOI: 10.1016/j.actbio.2013.12.016

Abstract

The contributions of mesolayers, organic interlamellar layers and nanoasperities/mineral bridges to the strength of nacre from red abalone (Haliotis rufescens) shell nacre are investigated. Samples were demineralized and deproteinized to separate the organic and mineral components, respectively. Tensile tests were performed on both the isolated organic constituent and the isolated mineral. The strength of the isolated organic component suggests that growth bands play an important role in the mechanical behavior as they are thick regions of protein that are a significant fraction (∼0.4) of the total organic content. The thickness variation of the nacre tablets was measured and found to be a small fraction of the mean tablet thickness (0.568μm); the standard deviation is 26nm, indicating that the wedge mechanism of toughening does not operate in the nacre investigated. Results obtained from the isolated mineral validate the importance of the organic constituent as the mechanical properties decline greatly when the organic component is removed. The results presented herein add to the understanding of the mechanical response of the organic interlayers and growth bands and their effect on the toughness of the abalone nacre.

Keywords: Mesolayers; Mineral bridges; Nacre; Organic constituent; Red abalone.

Publication types

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

MeSH terms

Animals
Biophysical Phenomena
Calcification, Physiologic
Gastropoda / anatomy & histology*
Gastropoda / physiology*
Gastropoda / ultrastructure
Minerals / chemistry*
Nacre / physiology*
Nanostructures / chemistry*
Nanostructures / ultrastructure
Tensile Strength

Substances

Minerals
Nacre