July 26, 2012
Recreating Nature: Scientists Copy Mother Of Pearl
redOrbit Staff & Wire Reports - Your Universe Online
Research published July 25 in the journal Nature Communications shows that scientists have for the first time copied the way mother of pearl is created.
The scientists wrote in a prepared statement: "Nacre, also called mother of pearl, is the iridescent coating that is found on the inside of some mollusks and on the outer coating of pearls. By recreating the biological steps that form nacre in mollusks, the scientists were able to manufacture a material which has a similar structure, mechanical behavior, and optical appearance of that found in nature."
The scientists followed three steps to create the artificial substance.
To begin with, the scientists took preventative measures to ensure the calcium carbonate, which is the primary component of mother of pearl, did not crystallize when precipitating from the solution. This was achieved by using a mixture of ions and organic components in the solution that mimics how mollusks control this. The precipitate could then be adsorbed to surfaces, forming layers of well-defined thickness.
After that, the precipitate layer was covered by an organic layer that has 10-nm wide pores, which was done in a synthetic procedure invented by co-author Alex Finnemore.
Lastly, crystallization was then induced, and all steps were repeated to create a stack of alternating crystalline and organic layers.
Professor Ulli Steiner, of the Department of Physics' Cavendish Laboratory at the University of Cambridge, said: "Crystals have a characteristic shape that reflects their atomic structure, and it is very difficult to modify this shape. Nature is, however, able to do this, and through our research we were able to gain insight into how it grows these materials. Essentially, we have created a new recipe for mother of pearl using nature's cookbook."
Alex Finnemore, also of the Department of Physics' Cavendish Laboratory, said: "While many composite engineering materials outperform nacre, its synthesis entirely at ambient temperatures in an aqueous environment, as well as its cheap ingredients, may make it interesting for coating applications. Once optimized, the process is simple and can easily be automated."