The remarkable properties of some natural materials have motivated many researchers to synthesize biomimetic nanocomposites that attempt to reproduce Nature’s achievements and to understand the toughening and deformation mechanisms of natural nanocomposite materials. One of the best examples is nacre, the pearly internal layer of many mollusc shells. It has evolved through millions of years to a level of optimization currently achieved in very few engineered composites. Preparation of artificial analogs of nacre has been approached by using several different methods and the resulting materials capture some of the characteristics of the natural composite
Nacre has a layered structure composed of approximately 95% calcium carbonate (CaCO3) and nearly 5% organics. As depicted in the figure below, single-crystalline calcium carbonate nanotablets (CCNs) are interfaced by entrapped organics. Such a periodic 'bricks and mortar' arrangement is crucial to mechanical and other outstanding properties that nacre possesses.