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Surface Heterogeneity of Trimethylphenylammonium-Smectite as Revealed by Adsorption of Aromatic Hydrocarbons from Water

Published online by Cambridge University Press:  28 February 2024

Guangyao Sheng
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, Michigan 48824
Shihe Xu
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, Michigan 48824
Stephen A. Boyd
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, Michigan 48824

Abstract

Adsorption studies of aromatic hydrocarbons of various molecular sizes on organo-clays in aqueous solution were carried out for characterizing the surface heterogeneity of organo-clays. Benzene, toluene, p-xylene, ethylbenzene and n-propylbenzene adsorption by a smectite with 5 different exchange degrees of trimethylphenylammonium (TMPA) cations for Ca2+ was measured. The Langmuir isotherm equation did not adequately describe the experimental data, especially for small molecules, whereas the Dubinin-Radushkevich (DR) equation combined with a gamma-type adsorption energy distribution function described all experimental data well, suggesting the surface and structural heterogeneity of TMPA-smectites. The calculated adsorption energy distributions indicated that the apparent heterogeneity depends on the molecular size of adsorbates. Small adsorbate molecules such as benzene explore a highly heterogeneous surface of TMPA-smectites while large molecules such as n-propylbenzene detect a relatively homogeneous surface. The surface fractal dimension was dependent on the extent of TMPA exchange for Ca2+. When TMPA content is less than 75% of the cation exchange capacity (CEC) of the smectite, the heterogeneity decreases as TMPA content increases; it increases with TMPA content thereafter. These results are related to the size distribution of micropores in TMPA-smectites, which are defined by the 2 semi-infinite aluminosilicate sheets and the interlayer cations. The micropore size distributions and, hence, heterogeneity are created in part by the inhomogeneity of the charge density of clay surfaces and the tendency for cation segregation in these systems.

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

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References

Avnir, D. Farm, D. and Pfeifer, P., 1983 Chemistry in noninteger dimensions between two and three. II. Fractal surfaces of adsorbents J Chem Phys 79 35663571 10.1063/1.446211.CrossRefGoogle Scholar
Avnir, D. Farin, D. and Pfeifer, P., 1984 Molecular fractal surfaces Nature 308 261263 10.1038/308261a0.CrossRefGoogle Scholar
Barrow, N.J. Brummer, G.W. and Strauss, R., 1993 Effects of surface heterogeneity on ion adsorption by metal oxides and by soils Langmuir 9 26062611 10.1021/la00034a020.CrossRefGoogle Scholar
Boyd, S.A. Jaynes, W.F. Ross, B.S. and Baker, R.S., 1991 Immobilization of organic contaminants by organo-clays: application to soil restoration and hazardous waste containment Organic substances and sediments in water, Vol 1 Boca Raton, FL CRC Pr 181200.Google Scholar
Boyd, S.A. Lee, J.-F. and Mortland, M.M., 1988 Attenuating organic contaminant mobility by soil modification Nature 333 345347 10.1038/333345a0.CrossRefGoogle Scholar
Boyd, S.A. Mortland, M.M. and Chiou, C.T., 1988 Sorption characteristics of organic compounds on hexadecyltrimethylam-monium-smectite Soil Sci Soc Am J 52 652657 10.2136/sssaj1988.03615995005200030010x.CrossRefGoogle Scholar
Brunauer, S. Emmett, P. and Teller, E., 1938 Adsorption of gases in multimolecular layers J Am Chem Soc 60 309319 10.1021/ja01269a023.CrossRefGoogle Scholar
Cerofolini, G.F., 1974 Localized adsorption on heterogeneous surfaces Thin Solid Films 23 129152 10.1016/0040-6090(74)90235-1.CrossRefGoogle Scholar
Choma, J. Burakiewicz-Mortka, W. Jaroniec, M. and Gilpin, R.K., 1993 Studies of the structural heterogeneity of micropo-rous carbons using liquid/solid adsorption isotherms Langmuir 9 25552561 10.1021/la00034a013.CrossRefGoogle Scholar
Dubinin, M.M., 1975 Physical adsorption of gases and vapors in micropores Prog Surf Membrane Sci 9 170 10.1016/B978-0-12-571809-7.50006-1.CrossRefGoogle Scholar
Dubinin, M.M., 1988 On methods for estimating micropore parameters of carbon adsorbents Carbon 26 9798 10.1016/0008-6223(88)90014-0.CrossRefGoogle Scholar
Dubinin, M.M. and Kadlec, O., 1987 Adsorption properties and microporous structures of carbonaceous adsorbents Carbon 25 593598 10.1016/0008-6223(87)90208-9.CrossRefGoogle Scholar
Dubinin, M.M. and Stoeckli, H.E., 1980 Homogeneous and heterogeneous micropore structures in carbonaceous adsorbents J Colloid Interface Sei 75 3442 10.1016/0021-9797(80)90346-X.CrossRefGoogle Scholar
Faver, H. and Lagaly, G., 1991 Organo-bentonites with quaternary alkylammonium ions Clay Miner 26 1932 10.1180/claymin.1991.026.1.03.CrossRefGoogle Scholar
Goldman, F. and Polanyi, M., 1928 Adsorption von dämpfen an kohle und die Wärmeausdehnung der benetzungsschicht Z Phys Chem 132 321370.CrossRefGoogle Scholar
Hobson, J.P., 1961 Physical adsorption of nitrogen on pyrex at very low pressures J Chem Phys 34 18501851 10.1063/1.1701099.CrossRefGoogle Scholar
Horvath, G. and Kawazoe, K., 1983 Method for the calculation of effective pore size distribution in molecular sieve carbon J Chem Eng Jpn 16 470475 10.1252/jcej.16.470.CrossRefGoogle Scholar
Innes, R.W. Fryer, J. and Stoeckli, H.E., 1989 On the correlation between micropore distribution obtained from molecular probes and from high resolution electron microscopy Carbon 27 7176 10.1016/0008-6223(89)90158-9.CrossRefGoogle Scholar
Jaroniec, M. and Derylo, A., 1981 Application of Dubinin-Ra-dushkevich-type equation for describing bisolute adsorption from dilute aqueous solution on activated carbon J Colloid Interface Sci 84 191195 10.1016/0021-9797(81)90274-5.CrossRefGoogle Scholar
Jaroniec, M. Gilpin, R.K. and Choma, J., 1993 Correlation between microporosity and fractal dimension of active carbons Carbon 31 325331 10.1016/0008-6223(93)90037-B.CrossRefGoogle Scholar
Jaroniec, M. Lu, X. Madey, R. and Avnir, D., 1990 Thermodynamics of gas adsorption on fractal surfaces of heterogeneous microporous solids J Chem Phys 92 75897595 10.1063/1.458196.CrossRefGoogle Scholar
Jaroniec, M. and Madey, R., 1988 Physical adsorption on heterogeneous solids Amsterdam, The Netherlands Elsevier.Google Scholar
Jaroniec, M. and Madey, R., 1989 A comprehensive theoretical description of physical adsorption of vapors on heterogeneous microporous solids J Phys Chem 93 52255230 10.1021/j100350a038.CrossRefGoogle Scholar
Jaynes, W.F. and Boyd, S.A., 1990 Trimethylphenylammonium-smectite as an effective adsorbent of water soluble aromatic hydrocarbons J Air Waste Manage Assoc 40 16491653 10.1080/10473289.1990.10466811.CrossRefGoogle ScholarPubMed
Jaynes, W.F. and Boyd, S.A., 1991 Clay mineral type and organic compound sorption by hexadecyltrimethylammonium-exchanged clays Soil Sci Soc Am J 55 4348 10.2136/sssaj1991.03615995005500010007x.CrossRefGoogle Scholar
Jaynes, W.F. and Boyd, S.A., 1991 Hydrophobicity of siloxane surfaces in smectites as revealed by aromatic hydrocarbon adsorption from water Clays Clay Miner 39 428436 10.1346/CCMN.1991.0390412.CrossRefGoogle Scholar
Kraehenbuehl, F. Stoeckli, H.F. Addoun, A. EhrBurger, P. and Donnet, J.B., 1986 The use of immersion calorimetry in the determination of micropore distribution of carbons in the course of activation Carbon 24 483488 10.1016/0008-6223(86)90272-1.CrossRefGoogle Scholar
Lagaly, G., 1979 The “layer charge” of regular interstratified 2:1 clay minerals Clays Clay Miner 27 110 10.1346/CCMN.1979.0270101.CrossRefGoogle Scholar
Lagaly, G., 1981 Characterization of clays by organic compounds Clay Miner 16 121 10.1180/claymin.1981.016.1.01.CrossRefGoogle Scholar
Lagaly, G., 1982 Layer charge heterogeneity in vermiculites Clays Clay Miner 30 215222 10.1346/CCMN.1982.0300308.CrossRefGoogle Scholar
Langmuir, I., 1918 The adsorption of gases on plane surfaces of glass, mica and platinum J Am Chem Soc 40 13611403 10.1021/ja02242a004.CrossRefGoogle Scholar
Lee, J.-F. Mortland, M.M. Chiou, C.T. Kile, D.E. and Boyd, S.A., 1990 Adsorption of benzene, toluene and xylene by two tetra-methylammonium-smectites having different charge densities Clays Clay Miner 38 113120 10.1346/CCMN.1990.0380201.CrossRefGoogle Scholar
McBride, M.B. and Mortland, M.M., 1973 Segregation and exchange properties of alkylammonium ions in a smectite and vermiculite Clays Clay Miner 21 323329 10.1346/CCMN.1973.0210508.CrossRefGoogle Scholar
Pfeifer, P. and Avnir, D., 1983 Chemistry in noninteger dimensions between two and three. I. fractal theory of heterogeneous surfaces J Chem Phys 79 35583565 10.1063/1.446210.CrossRefGoogle Scholar
Polanyi, M. and Welke, K., 1928 Adsorption, adsorptionswärme und bindungscharakter von schwefeldioxyd an kohle bei geringen belegungen Z Phys Chem 132 371383.CrossRefGoogle Scholar
Rudzinski, W. and Wojciechowski, B.W., 1993 Effects of surface heterogeneity in adsorption and catalysis on solids Langmuir 9 24832484 10.1021/la00034a600.CrossRefGoogle Scholar
Sheng, G. and Boyd, S.A., 1997 Relation of water and neutral organic compounds in the interlayers of mixed Ca/trime-thylphenylammonium-smectites Clays Clay Miner .Google Scholar
Sheng, G. Xu, S. and Boyd, S.A., 1996 Mechanism(s) controlling sorption of organic contaminants by surfactant-derived and natural organic matter Environ Sci Tech 30 15531557 10.1021/es9505208.CrossRefGoogle Scholar
Stoeckli, H.F., 1977 A generalization of the Dubinin-Radush-kevich equation for the filling of heterogeneous micropore systems J Colloid Interface Sci 59 184185 10.1016/0021-9797(77)90355-1.CrossRefGoogle Scholar
Stoeckli, H.F., 1989 On the description of micropore distributions by various mathematical models Carbon 27 6 962964 10.1016/0008-6223(89)90052-3.CrossRefGoogle Scholar
Stoeckli, H.F. Ballerini, L. and DeBernardini, S., 1989 On the evolution of micropore widths and areas in the course of activation Carbon 27 501502 10.1016/0008-6223(89)90088-2.CrossRefGoogle Scholar
Stoeckli, H.F. Rebstein, P. and Ballerini, L., 1990 On the assessment of microporosity in active carbons, a comparison of theoretical and experimental data Carbon 28 907909 10.1016/0008-6223(90)90339-Z.CrossRefGoogle Scholar
Xu, S. Sheng, G. and Boyd, S.A., 1997 Use of organoclays in pollution abatement Adv Agron 59 2562 10.1016/S0065-2113(08)60052-8.CrossRefGoogle Scholar