A Knack For Making Nacre

Abstract

The iridescent gleam of mother-of-pearl couldn’t come from more milquetoast materials. Mollusks make the stuff, also known as nacre, from calcium carbonate and a smattering of organic matter. Despite those simple ingredients, scientists have had a tough time producing the material in the lab. Now, researchers at England’s Cambridge University report a way to make artificial nacre for the first time using CaCO3 as the main component (Nat. Commun., DOI: 10.1038/ncomms1970). The new method could lead to tough coatings from inexpensive starting materials, the scientists say. Mollusks create nacre by depositing amorphous CaCO3 onto porous layers of the polysaccharide chitin. The mineral then crystallizes, producing stacks of CaCO3 that are separated by layers of organic material. The Cambridge team mimics this process by creating porous organic layers out of poly(acrylic acid) and poly(4-vinylpyridine) onto which amorphous CaCO3 is deposited and subsequently crystallized. The researchers repeat the process to ...