Skip to main content Accessibility help

Surface fractal dimensions of synthetic clay-hydrous iron oxide associations from nitrogen adsorption isotherms and mercury porosimetry

  • R. Cells (a1), J. Cornejo (a1) and M. C. Hermosin (a1)


Model associations of layer silicates (kaolinite and montmorillonite) and iron oxyhydroxides were obtained by precipitating hydrous iron oxide in clay suspensions at different loading. The porosity of these clay-hydrous iron oxide associations was studied in the macro- and mesopore range by mercury intrusion porosimetry (MIP) and in the micropore region by nitrogen adsorption isotherms, being the fractal geometry applied to the approaches used in porosity studies. Results of nitrogen adsorption isotherms showed that surface area and microporosity of kaolinite and montmorillonite increased upon Fe precipitation, especially for montmorillonite. This process is accompanied by an increase in the surface fractal dimension Ds(N2) by the presence of hydrous iron oxide coating the clay particles. Results of MIP also showed a decrease in the pore volume by Fe precipitation on montmorillonite due to a decrease in the number of large pores and a development of new medium-size pores. An increase of the fractal dimension Ds(Hg) was also observed.



Hide All
Avnir, D., Farin, D. & Pfeifer, P. (1984) Molecular fractal surfaces. Nature, 308, 261263.
Avnir, D. & Jaroniec, M. (1989) An isotherm equation for adsorption on fractal surfaces of heterogeneous porous materials. Langmuir, 5, 1431–1433.
Bartoli, F., Philippy, R. & Burtin, G. (1992) Poorly ordered hydrous Fe oxides, colloidal dispersion and soil aggregation.It. Modification of silty soil aggregation with Fe(III) polycations and model humic macromolecules. J. Soil Sci. 43, 59–75.
Bartoli, F., Philippy, R., Doirisse, M., Niquet, S. & Dubuit, M. (1991) Structure and self-similarity in silty and sandy soils: the fractal approach. J. Soil Sci. 42, 167185.
Ben Ohoud, M. & Van Damme, H. (1990) The fractal texture of swelling clays and clay-organic aggregates. C.R. Acad. Sci. Paris, 311, series II, 665-670.
Brunauer, S., Emmett, P.H. & Teller, E. (1938) Adsorption of gases in multimolecular layers. J. Am. Chem. Soc. 60, 309319.
Brunauer, S., Deming, L.S., Deming, W.S. & Teller, E. (1940) On a theory of the Van der Waals adsorption of gases. J. Am. Chem. Soc. 62, 17231732.
Burrough, P.A. (1981) Fractal dimensions of landscapes and other environmental data. Nature, 294, 240242.
Cornejo, J. (1987) Porosity evolution of thermally treated hydrous ferric oxide gel. J. Coll. lnterfi Sci. 115, 260263.
Cornejo, J., Serna, C.J. & Hermosin, M.C. (1984) Nitrogen adsorption on synthetic ferrihydrite. J. Coll. lnterf. Sci. 94, 546551.
Cox, L., Celis, R., Hermosin, M.C. & Cornejo, J. (1996) Porosity, sorption and surface fractal properties of soils as factors affecting mobility of herbicides. Eur. J. Soil Sci. (submitted).
De Gennes, P.G. (1985) Partial filling of a fractal structure by a wetting fluid. Pp. 227–241 in: Physics of Disordered Materials. (Adler, D. et al., editors). Plenum Press, New York.
Desphande, T.L., Greenland, D.J. & Quirk, J.P. (1964) Role of iron oxides in the bonding of soil particles. Nature, 201, 107108.
Dubinin, M.M. (1988) Characterization of Porous Solids. (Unger, K.K., Rouquerol, J., Sing, K.S.W. & Kral, H., editors). Elsevier, Amsterdam.
El Rayan, H.M.E. & Rowell, D.L. (1973) The influence of iron and aluminum hydroxides on the swelling of Na-montmorillonite and the permeability of a Nasoil. J. Soil Sci. 24, 137144.
Friesen, W.I. & Mlula, R.J. (1987) Fractal dimensions of coal particles. J. Coll. lnterfi. Sci. 120, 263271.
Goldberg, S. & Glaubig, R.A. (1987) Effect of saturating cation, pH, and aluminum and iron oxide on the flocculation of kaolinite and montmorillonite. Clays Clay Miner. 35, 220227.
Gregg, S.J. & Sing, K.S.W. (1982) Adsorption, Surface Area and Porosity, pp. 89–90. Academic Press Inc., London.
Horvath, G. & Kawazoe, K. (1983) Method for the calculation of effective pore size distribution in molecular sieve carbon. J. Chem. Eng. Japan, 16, 470475.
Lefebvre, Y., Lacelle, S. & Jolicoeur, C. (1992) Surface fractal dimensions of some industrial minerals from gas-phase adsorption isotherms. J. Mat. Res. 7, 18881891.
Mandelbrot, I. (1982) The Fractal Geometry of Nature. Freeman, San Francisco.
Pfeifer, P. & Avnir, O. (1983) Chemistry in noninteger dimensions between two and three. J. Chem. Phys. 79, 35583565.
Shahmuganathan, R.T. & Oades, J.M. (1982) Modification of soil physical properties by manipulating the net surface charge on colloids through addition of Fe(III) polycations. J. Soil Sci. 33, 451465.
Shepard, S.J. (1993) Using a fractal model to compute the hydraulic conductivity function. Soil Sci. Soc. Am. J. 57, 300306.
Srasra, E., Bergaya, F., Van Damme, H. & Ariguib, N.K. (1989) Surface properties of an activated bentonitedecolorisation of rape-seed oils. Appl. Clay Sci. 4, 411421.
Van Damme, H., Levrrz, P., Gattneau, L., Alcover, J.F. & Fripiat, J.J. (1988) On the determination of the surface fractal dimension of powders by granulometric analysis. J. Coll. lnte.rfi Sci. 122, 18.
Van Olphen, H. & Fripiat, J.J. (1979) Data Handbook for Clay Materials and other Non-Metallic Minerals. OECD and Clay Minerals Society. Pergamon Press, Oxford.
Washburn, E.W. (1921) Note on a method of determining the distribution of pore sizes in a porous material. Proc. Nat. Acad. Sci. U.S.A. 7, 115-116.
Young, I.M. & Crawford, J.W. (1991) The fractal structure of soil aggregates: its measurement and interpretation. J. Soil Sci. 42, 187192.

Surface fractal dimensions of synthetic clay-hydrous iron oxide associations from nitrogen adsorption isotherms and mercury porosimetry

  • R. Cells (a1), J. Cornejo (a1) and M. C. Hermosin (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed