抄録
In biomineralization process, the nacre layer takes a brick and mortar arrangement. The bricks are flat crystals of aragonite, and organic film glues the aragonite crystals as mortar. The sizes, shapes and crystallographic directions of calcium carbonate formed highly regulated due to inorganic-organic interfacial interactions. We attempted to control phase and crystal growth direction of calcium carbonate on organic molecular assemblies. Polymerized 10,12-pentacosadiynoic acid film was prepared by Langmuir-Blodgett method and soaked in supersaturated calcium bicarbonate solution containing Mg ion ([Mg2+]/[Ca2+] = 10) and small Sr ion. After soaking, acicular aragonite crystals of about 10 micron in size were found on the film surface. The a-axis of the aragonite crystal was parallel to longitudinal direction of the acicular aragonite crystal. Calcite is thermodynamically most stable at ambient temperature and pressure, but aragonite crystals nevertheless grew on organic thin film in the solution containing Mg and Sr ions.
