Nanocrystallization of CaCO3 at solid/liquid interfaces in magnetic field:: A quantum approach

With the application of 1.2 T external magnetic field, 90% of CaCO(3) soluble molecules in water flow precipitate on stainless steel 316 solid/liquid interface in the form of aragonite/vaterite. The magnetic field increases locally the thermodynamic potentials at interface, favoring the formation of aragonite than calcite, despite the fact that the field-free ground electronic state of aragonite is situated higher than of calcite. A quantum mechanical model predicts that magnetic fluctuations inside the liquid can be amplified by exchanging energy with an external magnetic field through the angular momentum of the water molecular rotors and with the macroscopic angular momentum of the turbulent flow. The theoretical model predicts that the gain is higher when the magnetic field is in resonance with the rotational frequencies of the molecular rotors or/and the low frequencies of the turbulent flow and that aragonite concentration is increasing at 0.4 T in agreement with the experimental results. Contrary to calcite, aragonite binds weakly on flow surfaces; and hence the process has significant industrial, environmental and biological impact. (C) 2008 Elsevier B. V. All rights reserved.