Nanostructured individual nacre tablet: a subtle designed organic–inorganic composite

Abstract

From natural evolution, nacre, a biogenic organic–inorganic composite, fulfils an ingenious combination of remarkable strength and toughness. Its basic building block, the individual nacre tablet, assumes an important mechanical function. Unravelling its design strategies can hence provide essential information for the pursuit of high-performance artificial composites. Here, the nanostructure inside the individual nacre tablet (Pinctada maxima) was investigated using transmission electron microscopy techniques. Results show that organic matter is trapped inside the tablet in both an islet-like and sheet-like manner. More interestingly, the crystal structure of aragonite scaffold is continuous and homodromous throughout the whole tablet even in this case. A biomineralization mechanism of the tablet is discussed based on this finding.