Crystallization of Sodium Bicarbonate in the Presence of Trace Amounts of HPMA

摘要

The effect of trace amounts of hydrolytic polymaleic anhydride (HPMA) on the crystallization of sodium bicarbonate (NaHCO3) has been investigated by molecular simulation and experimen- tal methods. Cooling crystallization experiments show that the trace HPMA molecule effectively promotes the formation of larger NaHCO3 crystals. Besides, the crystal morphology changes from needle-like to flake-like. The determination of the metastable zone width of NaHCO3 and Atomic Force Micro- scopy (AFM) observation confirmed that the spontaneous nucleation processes are suppressed. Molecule simulation was used to explore the interaction of HPMA molecule and different crystal faces of NaHCO3. It was found that the binding energy between HPMA and NaHCO3 surface is greater than the corresponding attachment energy of NaHCO3 surface. The electrostatic interaction energy between double-bonded oxy- gen on the HPMA molecule and the Na+ of the NaHCO3 crystal plane plays a dominant role in the additive molecule‘s adsorption on the NaHCO3 crystal surface. This work suggests that HPMA could serve as an inhibitor of nucleation and impact NaHCO3 crystallization.