Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-09T20:17:11.915Z Has data issue: false hasContentIssue false

The surface energies of cation substituted Laponite

Published online by Cambridge University Press:  09 July 2018

J. Norris
Affiliation:
Department of Geology, State University of New York, 4240 Ridge Lea, Amherst NY 14226
R. F. Giese
Affiliation:
Department of Geology, State University of New York, 4240 Ridge Lea, Amherst NY 14226
P. M. Costanzo
Affiliation:
Unilever Research, US, Inc., 45 River Road, Edgewater NJ 07020
C. J. van Oss
Affiliation:
Departments of Microbiology and Chemical Engineering, State University of New York, 3435 Main Street, Buffalo NY 14214, USA

Abstract

Laponite RD forms stable, coherent films which adhere strongly to glass slides. Such films are capable of supporting liquid drops allowing the direct measurement of contact angles for five liquids of which, two were apolar (0:-bromonaphthalene and diiodomethane) and three were polar (water, formamide, glycerol); surface tension components and parameters (γLw, γ and γ) were determined by solving the Young equation. These determinations were made for homoionic samples saturated with Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba and NH4 as well as the natural material. Whereas the values of γLw (the apolar Lifshitz-van der Waals component) varied only within narrow limits (41-44 mJ/m2), the Lewis base parameter varied comparatively widely (24-41 mJ/m2). The Lewis acid parameter was small and relatively constant (1·3-3·0 mJ/m2). The variation of γ as a function of the exchangeable cation suggests that the divalent cations are shielded from the silicate surface by the water molecules of their sphere of hydration, whereas the monovalent cations are in direct contact with the oxygen atoms of the silicate surface. Furthermore, the divalent cations may screen the Lewis base sites to a greater degree than do the monovalent cations. Lithium behaves anomalously and this may indicate that it physically enters into the ditrigonal hole in the silicate layer.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ames, L.L. Jr., Sand, L.B. & Goldich, S.S. (1958) A contribution on the Hector, California bentonite deposit. Econ. Geol. 5, 2237.CrossRefGoogle Scholar
Bleam, W.F. (1990) The nature of cation-substitution sites in phyllosilicates. Clays Clay Miner. 38, 527536.CrossRefGoogle Scholar
Chaudhury, M.K. (1984) Short range and long range forces in colloidal and macroscopic systems. PhD thesis, Suny at Buffalo, Usa.Google Scholar
Farmer, V.C. (1978) Water on particle surfaces. Pp. 405-448 in: The Chemistry of Soil Constituents (D.J. Greenland & M.H.B Hayes, Editors). Wiley, New York.Google Scholar
FripiaT, J.J. (1981) Advanced Techniques for Clay Mineral Analysis. Developments in Sedimentology 34, Elsevier Scientific Publishing Co.Google Scholar
Giese, R.F., Cosxanzo, P.M. & Van OSS, C. J. (1991) The surface free energies of talc and pyrophyllite. Phys. Chem. Minerals 17, 611616.CrossRefGoogle Scholar
Giese, R.F., Van OSS, C.J., Norris, J. & Costanzo, P.M. (1990) Surface energies of some smectite clay minerals. Proc. 9th Int. Clay Conf., Strasbourg II, 33-42.Google Scholar
Holysz, L. & Chibowski, E. (1992) Surface free energy components and floatability of barite precovered with sodium dodecyl sulfate. Langmuir 8, 303308.CrossRefGoogle Scholar
Janczuk, B. & Bialopiotrowicz, Z. (1988) Components of surface free energy of some clay minerals. Clays Clay Miner. 36, 243248.Google Scholar
Jouany, C. (1991) Surface free energy components of clay-synthetic humic acid complexes from contact-angle measurements. Clays Clay Miner. 39, 4349.CrossRefGoogle Scholar
Kinniburgh, D.G. (1981) Cation adsorption by hydrous met al oxides and clays. Pp. 91-160 in: Adsorption of Inorganics at Solid-liquid Interfaces (M.A. Anderson & A.J. Rubin, Editors). Ann Arbor Science Publishers Inc. Ann Arbor, Mi.Google Scholar
Latimer, W.M., Pitzer, K.S. & Slansky, W.V. (1939) The free energy of hydration of gaseous ions and the absolute potential of the normal calomel electrode. J. Chem. Phys. 7, 108111.Google Scholar
Neumann, B.S. & Sansom, K.G. (1970) The formation of stable sols from Laponite, A synthetic hectorite-like clay. Clay Miner. 8, 389404.Google Scholar
Ohki, S. (1982) A mechanism of divalent ion-induced phosphatidylserine membrane fusion. Biochim. Biophys. Acta 689, 111.Google Scholar
Press, W.H., Flannery, B.P., Teukolsky, S.A. & Vetferling, W.T. (1986) Numerical Recipes. Cambridge University Press, New York.Google Scholar
Ramsay, J.D.F. (1986) Colloidal properties of synthetic hectorite clay dispersions. J. Coll. Interf. Set 109, 441454.Google Scholar
Schrader, M.E. & Yariv, S. (1990) Wettability of clay minerals. J. Coll. Interf. Sci. 136, 8594.Google Scholar
Taylor, J. & Neumann, B.S. The nature of synthetic swelling clays and their use in emulsion paint. J. Oil Col. Chem. Assoc. 51, 232253.Google Scholar
Van Oss, C.J., Chaudhury, M.K. & Good, R.J. (1988) Interracial Lifshitz-van der Waals and polar interactions in macroscopic systems. Chem. Rev. 88, 927941.CrossRefGoogle Scholar
Van Oss, C.J., Giese, R.F. & Costanzo, P.M. (1990) DLVO and non-DLVO interactions in hectorite. Clays Clay Miner. 38, 151159.Google Scholar
Van Oss, C.J. & Good, R.J. (1992) Prediction of the solubility of polar polymers by means of interracial tension combining rules. Langmuir 8, 28772879.CrossRefGoogle Scholar