MECHANISM OF SOLID LIQUID INTERFACIAL REACTIONS - THE MALEIC-ACID DRIVEN DISSOLUTION OF CALCITE - AN ATOMIC-FORCE MICROSCOPY STUDY UNDER DEFINED HYDRODYNAMIC CONDITIONS/
Q. Hong et al., MECHANISM OF SOLID LIQUID INTERFACIAL REACTIONS - THE MALEIC-ACID DRIVEN DISSOLUTION OF CALCITE - AN ATOMIC-FORCE MICROSCOPY STUDY UNDER DEFINED HYDRODYNAMIC CONDITIONS/, JOURNAL OF PHYSICAL CHEMISTRY B, 101(28), 1997, pp. 5557-5564
The dissolution of calcite (CaCO3) in the presence of aqueous solution
s containing maleic acid (cis-HOOC-CH=CH-COOH) in the pH range 4.3-8.2
has been studied by means of atomic force microscopy utilizing a flow
cell of known hydrodynamics and modelable convection/diffusion. The l
atter permits the interpretation of dissolution rate data as measured
by the z-piezo voltage in terms of a mechanism involving concentration
s of solution species local to the dissolving crystal surface. In this
way the dissolution mechanism for the (<10(1)over bar 4>) cleavage pl
ane is shown to proceed via reaction of the adsorbed monoprotonated an
ion, cis-HOOC-CH=CH-COO-, but to be inhibited by the adsorbed dianion,
-OOC-CH=CH-COO-. Where available excellent quantitative agreement is
noted with independent surface averaged kinetic data previously (J. Ch
em. Sec., Faraday Trans. 1 1989, 85, 4335) obtained using a channel fl
ow cell.