Abstract

Nacre, the crown jewel of natural materials, has been extensively studied owing to its remarkable physical properties for over 160 years. Yet, the precise structural features governing its extraordinary strength and its growth mechanism remain elusive. In this paper, we present a series of observations pertaining to the red abalone (Haliotis rufescens) shell's organic-inorganic interface, organic interlayer morphology and properties, large-area crystal domain orientations and nacre growth. In particular, we describe unique lateral nano-growths and paired screw dislocations in the aragonite layers, and demonstrate that the organic material sandwiched between aragonite platelets consists of multiple organic layers of varying nano-mechanical resilience. Based on these novel observations and analysis, we propose a spiral growth model that accounts for both [001] vertical propagation via helices that surround numerous screw dislocation cores and simultaneous 010 lateral growth of aragonite sheet structure. These new findings may aid in creating novel organic-inorganic micro/nano composites through synthetic or biomineralization pathways.

View details for DOI 10.1098/rsif.2008.0316

View details for Web of Science ID 000264357800004

View details for PubMedID 18753125

View details for PubMedCentralID PMC2572677