Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-23T07:04:58.108Z Has data issue: false hasContentIssue false

Surface Charge Properties of Kaolinite

Published online by Cambridge University Press:  28 February 2024

Brian K. Schroth
Affiliation:
Division of Ecosystem Sciences, Hilgard Hall #3110, University of California, Berkeley, California 94720-3110
Garrison Sposito
Affiliation:
Division of Ecosystem Sciences, Hilgard Hall #3110, University of California, Berkeley, California 94720-3110
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 surface charge components of 2 Georgia kaolinites of differing degrees of crystallinity (KGa-1 and KGa-2) were determined using procedures based on charge balance concepts. Permanent structural charge density (σ0) was determined by measuring the surface excess of Cs, which is highly selective to permanent charge sites. The values of σ0 determined were -6.3 ± 0.1 and -13.6 ± 0.5 mmol kg−1 for kaolinites KGa-1 and KGa-2, respectively. The net proton surface charge density (σH) was determined as a function of pH by Potentiometrie titration in 0.01 mol dm-3 LiCl. Correction from apparent to absolute values of σH was made by accounting for Al release during dissolution, background ion adsorption and charge balance. Lithium and C1 adsorption accounted for the remainder of the surface charge components. Changes in surface charge properties with time were measured after mixing times of 1, 3 and 15 h, the latter representing “equilibrium”. Time-dependent behavior is believed to be caused by mineral dissolution followed by readsorption or precipitation of Al on the mineral surface. Both the point of zero net charge (p.z.n.c.) and the point of zero net proton charge (p.z.n.p.c.) changed with mixing time, generally increasing. The “equilibrium” p.z.n.c. values were approximately 3.6 for KGa-1 and 3.5 for KGa-2, whereas the corresponding p.z.n.p.c. values were about 5.0 and 5.4. The p.z.n.c. results were in good agreement with previous studies, but the values of p.z.n.p.c. were higher than most other values reported for specimen kaolinite.

Type
Research Article
Copyright
Copyright © 1997, The Clay Minerals Society

References

Anderson, S.J. and Sposito, G.. 1991. Cesium adsorption method for measuring accessible structural surface charge. Soil Sci Soc Am J 55: 15691576.CrossRefGoogle Scholar
Anderson, S.J. and Sposito, G.. 1992. Proton surface charge density in soils with structural and pH dependent charge. Soil Sci Soc Am J 56: 14371443.CrossRefGoogle Scholar
Bolland, M.D.A., Posner, A.M. and Quirk, J.P.. 1976. Surface charge on kaolinites in aqueous suspension. Aust J Soil Res 14: 197216.CrossRefGoogle Scholar
Braggs, B., Fornasiero, D., Ralston, J. and St Smart, R.. 1994. The effect of surface modification by an organosilane on the electrochemical properties of kaolinite. Clays Clay Miner 42: 123136.CrossRefGoogle Scholar
Buchanan, A.S. and Oppenheim, R.C.. 1968. The surface chemistry of kaolinite. I. Surface leaching: Aust J Chem 21: 23672371.Google Scholar
Carroll-Webb, S.A. and Walther, J.V.. 1988. A surface complex reaction model for the pH-dependence of corundum and kaolinite dissolution rates. Geochim Cosmochim Acta 52: 26092623.CrossRefGoogle Scholar
Charlet, L. and Sposito, G.. 1987. Monovalent ion adsorption by an Oxisol. Soil Sci Soc Am J 51: 11551160.CrossRefGoogle Scholar
Charlet, L., Schindler, P.W., Spadini, L., Furrer, G. and Zysset, M.. 1993. Cation adsorption on oxides and clays: The aluminum case. Aquatic Sci 55: 291303.CrossRefGoogle Scholar
Chorover, J. and Sposito, G.. 1993. Measurement of soil surface charge components. Technical report, NSF grant EAR9221258. Berkeley: Univ of California. 48 p.Google Scholar
Chorover, J. and Sposito, G.. 1995a. Surface charge characteristics of kaolinitic tropical soils. Geochim Cosmochim Acta 59: 875884.CrossRefGoogle Scholar
Chorover, J. and Sposito, G.. 1995b. Dissolution behavior of kaolinitic tropical soils. Geochim Cosmochim Acta 59: 31093121.CrossRefGoogle Scholar
Ferris, A.P. and Jepson, W.B.. 1975. The exchange capacities of kaolinite and the preparation of homoionic clays. J Colloid Interface Sci 51: 245259.CrossRefGoogle Scholar
Goldberg, S., Davis, J.A. and Hem, J.D.. 1996. The surface chemistry of aluminum oxides and hydroxides. In: Sposito, G., editor. The environmental chemistry of aluminum, 2nd ed. Boca Raton, FL: CRC Pr. p 271331.Google Scholar
Gran, G.. 1952. Determination of the equivalence point in potentiometric titrations. Part II. Analyst 77: 661671.CrossRefGoogle Scholar
Haderlein, S.B. and Schwarzenbach, R.P.. 1993. Adsorption of substituted nitrobenzenes and nitrophenols to mineral surfaces. Environ Sci Technol 27: 316326.CrossRefGoogle Scholar
Jepson, W.B.. 1984. Kaolins: Their properties and uses. Phil Trans R Soc Lond A311: 411432.Google Scholar
Kim, Y., Cygan, R.T. and Kirkpatrick, R.J.. 1996. 133Cs NMR and XPS investigation of cesium adsorbed on clay minerals and related phases. Geochim Cosmochim Acta 60: 10411052.CrossRefGoogle Scholar
Lim, C.H., Jackson, M.L., Koons, R.D. and Helmke, P.A.. 1980. Kaolins: Sources of differences in cation-exchange capacities and cesium retention. Clays Clay Miner 28: 223229.CrossRefGoogle Scholar
Lyklema, J.. 1987. Electrical double layers on oxides: Disparate observations and unifying principles. Chem Ind 65: 741747.Google Scholar
Motta, M.M. and Miranda, C.F.. 1989. Molybdate adsorption on kaolinite, montmorillonite, and illite: Constant capacitance modeling. Soil Sci Soc Am J 53: 380385.CrossRefGoogle Scholar
Nordstrom, D.K. and May, H.M.. 1996. Aqueous equilibrium data for mononuclear aluminum species. In: Sposito, G., editor. The environmental chemistry of aluminum, 2nd ed. Boca Raton, FL: CRC Pr. p 3980.Google Scholar
Olphen, H van and Fripiat, J.J.. 1979. Data handbook for clay materials and other non-metallic minerals. NY: Pergamon Pr. p 1318.Google Scholar
Parks, G.A.. 1967. Aqueous surface chemistry of oxides and complex oxide minerals. In: Equilibrium concepts in natural water systems. Washington, DC: Am Chem Soc. p 121160.Google Scholar
Schindler, P.W., Liechti, P. and Westall, J.C.. 1987. Adsorption of copper, cadmium and lead from aqueous solution to the kaolinite/water interface. Neth J Agric Sci 35: 219230.Google Scholar
Sposito, G.. 1992. Characterization of particle surface charge. In: Buffle, J., Leeuwen, v.a.n., editors. Environmental particles. Chelsea, MI: Lewis Publ. p 291314.Google Scholar
Steel, R.G.D. and Torrie, J.H.. 1960. Principles and procedures of statistics, with special reference to the biological sciences. NY: McGraw-Hill. 481 p.Google Scholar
Stumm, W.. 1992. Chemistry of the solid-water interface. NY: J Wiley. 428 p.Google Scholar
Sverjensky, D.A.. 1994. Zero-point-of-charge prediction from crystal chemistry and solvation theory. Geochim Cosmochim Acta 58: 31233129.CrossRefGoogle Scholar
Wieland, E. and Stumm, W.. 1992. Dissolution kinetics of kaolinite in acidic aqueous solutions at 25 °C. Geochim Cosmochim Acta 56: 33393355.CrossRefGoogle Scholar
Xie, Z. and Walther, J.V.. 1992. Incongruent dissolution and surface area of kaolinite. Geochim Cosmochim Acta 56: 33573363.CrossRefGoogle Scholar
Zhou, Z. and Gunter, W.D.. 1992. The nature of the surface charge of kaolinite. Clays Clay Miner 40: 365368.CrossRefGoogle Scholar