Mineralization of calcite ribbons on an Allium fistulosum L. bulb inner membrane in an ethanol-water mixed solvent under control of polyacrylic acid by a double diffusion method

This paper describes the mineralization and morphosynthesis of CaCO ₃ on an Allium fistulosum L. bulb inner membrane by a double diffusion method and exhibits some ingenious structures of CaCO₃ formed on both surfaces of the bulb membrane. Novel calcite ribbons with smooth surfaces and film coatings consisting of petal-like building blocks have been synthesized on the inner and outer surface of the bulb membrane when two surfaces faced CaCl₂ solution, respectively. The presence of polyacrylic acid (PAA), a suitable pH value and the mixed solvent system are the key primary conditions for the formation of calcite ribbons. The surface of the bulb membrane acted as an insoluble matrix providing nucleation sites for CaCO₃ crystals with different morphologies. The present double diffusion method involved using a plant system and its combination with a polyelectrolyte in a mixed solvent system provides a versatile, mild and flexible tool to control the size and shape of CaCO₃ crystals, which may be extended for synthesis of other inorganic materials.