How nature grows one tough biomineral

Abstract

By weaving tiny bits of protein into the lattices of growing crystals, nature long ago figured out how to convert calcium carbonate, a brittle, fragile material, to the tough biomineralized form of calcite, the carbonate-based material from which seashells and some animal claws are made. Just recently, scientists figured out how nature does it. The new study shows that the mechanism controlling calcite crystallization is directed by surface chemistry, not simple physical processes, as had been commonly assumed. The findings could lead to new strategies for synthesizing tough composites and CO2 storage materials. Materials scientist James J. De Yoreo of Pacific Northwest National Laboratory described his team’s study at the American Chemical Society national meeting in San Diego last week. To probe the biomineralization process, De Yoreo and colleagues exposed a freshly cleaved calcite crystal to a concentrated water-based solution of calcium carbonate in an atomic force microscopy liquid sample