Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-10T09:57:03.124Z Has data issue: false hasContentIssue false

Dissolution of Brucite on the (001) Surface at Neutral pH: in situ Atomic Force Microscopy Observations

Published online by Cambridge University Press:  01 January 2024

Yuriko Kudoh
Affiliation:
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
Jun Kameda
Affiliation:
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
Toshihiro Kogure*
Affiliation:
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
*
*E-mail address of corresponding author: kogure@eps.s.u-tokyo.ac.jp
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The dissolution of brucke, Mg(OH)2, on the (001) surface was investigated using in situ atomic force microscopy in solutions at near-neutral pH. Dissolution proceeded by the formation of crystallographically oriented triangular etch pits with monolayer step and expansion of the pits. The sides of the triangle are parallel to the [100], [110] and [010] directions of the brucite structure, and the orientation of lines from the center of the triangle to the three apices are along the [210], [1¯10]$[\bar 110]$ and [1¯2¯0]$[\bar 1\bar 20]$ directions. This orientation may produce pit edges where OH groups coordinate to two Mg2+. Although triangular etch pits with monolayer depth formed mostly at random on the (001) surface, concentric pits penetrating several layers were also observed. Etch pits with spiral steps were rarely observed. Coalescence of the pits resulted in stranded terraces that diminished in size rapidly and formed a rounded irregular form. The step-retreat velocity around the triangular pit is 0.015–0.04 nm/s at pH 5–8. The retreat velocity around the stranded terraces was about three times more rapid than that around the triangular etch pits.

Type
Research Article
Copyright
Copyright © 2006, The Clay Minerals Society

References

Arvidson, R.S. Ertan, I.E. Amonette, J.E. and Luttge, A., (2003) Variation in calcite dissolution rates: A fundamental problem? Geochimica et Cosmochimica Acta 67 16231634 10.1016/S0016-7037(02)01177-8.CrossRefGoogle Scholar
Binning, G. Quate, C.F. and Gerber, C.h., (1986) Atomic Force Microscope Physical Review Letters 56 930933 10.1103/PhysRevLett.56.930.CrossRefGoogle Scholar
Bosbach, D. and Rammensee, W., (1994) In situ investigation of growth and dissolution on the (010) surface of sypsum by Scanning Force Microscopy Geochimica et Cosmochimica Acta 58 843849 10.1016/0016-7037(94)90509-6.CrossRefGoogle Scholar
Dove, P.M. and Platt, F.M., (1996) Compatible real-time rates of mineral dissolution by Atomic Force microscopy (AFM) Chemical Geology 127 331338 10.1016/0009-2541(95)00127-1.CrossRefGoogle Scholar
Heaton, J.S. and Engstrom, R.C., (1994) In situ atomic force microscopy study of the differential dissolution of fayalite and magnetite Environmental Science and Technology 28 17471754 10.1021/es00058a028.CrossRefGoogle ScholarPubMed
Jordan, G. and Rammensee, W., (1996) Dissolution rates and activation energy for dissolution of brucite (001): A new method based on the microtopography of crystal surfaces Geochimica et Cosmochimica Acta 60 50555062 10.1016/S0016-7037(96)00309-2.CrossRefGoogle Scholar
Jordan, G. Higgins, S.R. and Eggleston, C.M., (1999) Dissolution of the periclase (001) surface: A scanning force microscope study American Mineralogist 84 144151 10.2138/am-1999-1-216.CrossRefGoogle Scholar
Kogure, T., (2002) Identification of polytypic groups in hydrous phyllosilicates using electron back-scattering patterns American Mineralogist 87 16781685 10.2138/am-2002-11-1217.CrossRefGoogle Scholar
Lasaga, A.C. and Luttge, A., (2003) A model for crystal dissolution European Journal of Mineralogy 15 603615 10.1127/0935-1221/2003/0015-0603.CrossRefGoogle Scholar
Peskleway, C.D. Henderson, G.S. and Wicks, F.J., (2003) Dissolution of gibbsite: Direct observations using fluid cell atomic force microscopy American Mineralogist 88 1826 10.2138/am-2003-0103.CrossRefGoogle Scholar
Pokrovsky, O.S. and Schott, J., (2004) Experimental study of brucite dissolution and precipitation in aqueous solutions: Surface speciation and chemical affinity control Geochimica et Cosmochimica Acta 68 3145 10.1016/S0016-7037(03)00238-2.CrossRefGoogle Scholar
Pokrovsky, O.S. Schott, J. and Castillo, A., (2005) Kinetics of brucite dissolution at 25°C in the presence of organic and inorganic ligands and divalent metals Geochimica et Cosmochimica Acta 69 905918 10.1016/j.gca.2004.08.011.CrossRefGoogle Scholar
Rufe, E. and Hochella, M.F., (1999) Quantitative assessment of reactive surface area of phlogopite during acid dissolution Science 285 874876 10.1126/science.285.5429.874.CrossRefGoogle ScholarPubMed
Shiraki, R. Rock, P. and Casey, W.H., (2000) Dissolution kinetics of calcite in 0.1 M NaCl solution at room temperature: An atomic force microscope (AFM) study Aquatic Geochemistry 6 87108 10.1023/A:1009656318574.CrossRefGoogle Scholar
Vermilyea, D.A., (1969) The dissolution of MgO and Mg(OH)2 in aqueous solutions Journal of Electrochemical Society 116 11791183 10.1149/1.2412273.CrossRefGoogle Scholar
White, A.F. and Brantley, S.L., (1995) Chemical Weathering Rates of Silicate Minerals Washington, D.C Mineralogical Society of America 10.1515/9781501509650.CrossRefGoogle Scholar