The English scientists for the first time managed to create the full copy of nacre – natural material which covers an internal cavity of sinks of mollusks and is the main construction material of pearls. By estimates of experts, the man-made product even surpasses a precious natural analog in durability and optical properties.
Until recently attempts of chemists of the whole world to recreate nacre in the conditions of laboratory remained unsuccessful. The form of crystals at a natural masterpiece reflects their atomic structure therefore to reproduce identical artificial processes extremely difficult.
Natural nacre is a unique organiko-inorganic composite: parallel layers of aragonite (a carbonate of calcium, CaCO3) are divided among themselves by porous biopolymers, such as chitin. Multiple layers and orderliness of structure do nacreous deposits by 3,000 times by stronger, than material of a basis - aragonite.
Chemists already created the artificial products which are brought closer to nacre on technical characteristics. So, one of research groups used for layered structure aluminum oxide instead of CaCO3. The received material differed in durability, however had faded white color. Meanwhile, thickness of crystals of aragonite in a natural analog is comparable with visible light waves – therefore nacre and is poured by all colors of the rainbow. Scientists of the Cambridge university managed to understand completely natural process and to successfully reproduce nacre by means of CaCO3. First of all, they needed to create a basis of man-made structure - a carbonate of calcium which at sedimentation from solution will not begin to crystallize. "Cookbook" of the nature itself prompted the recipe of artificial nacre. The natural material used by mollusks was recreated: researchers added inorganic ions of magnesium and organic components to CaCO3 solution. Being besieged, aragonite was absorbed on subject glass and formed layers of identical thickness. At the second stage of creation of nacre the sedimentary layer of a carbonate of calcium became covered by a porous layer of organic chemistry. At last, at the third stage of researches there was a crystallization of the artificial created covering. As a result of repeated repetition of the described process the "sandwich" consisting of crystal and organic layers – long-awaited artificial nacre in vitro was formed. By estimates of scientists, it even surpasses natural material in the durability and iridescence of gloss. Experts assure that at a man-made masterpiece the big future. Thanks to availability of materials to its reproduction, the innovative product can find the place in the world industrial industry. In particular, it can be applied to production of anticorrosion coatings.