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Methylene Blue Dimerization Does Not Interfere in Surface-Area Measurements of Kaolinite and Soils

Published online by Cambridge University Press:  28 February 2024

Marcelo J. Avena
Affiliation:
INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
Laura E. Valenti
Affiliation:
INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
Valeria Pfaffen
Affiliation:
INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
Carlos P. De Pauli*
Affiliation:
INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
*
*E-mail address of corresponding author: depauli@fisquim.fcq.unc.edu.ar

Abstract

Methylene blue (MB) was adsorbed from aqueous solutions onto a kaolinite and four soil samples to determine the effects of MB dimerization on the measured surface area. Adsorption isotherms were prepared using four adsorbing solutions containing, respectively, 9, 46, 71, and 83% of MB molecules in the dimeric state. Langmuir-type isotherms were obtained in each case. The results indicate that equilibration occurs quickly. The aggregation state of MB molecules at the surface does not depend on the aggregation state in the initial adsorbing solutions, but on the final equilibrium concentration of MB. A comparison with the specific surface area measured by adsorption of ethylene glycol monoethyl ether indicates that MB adsorbs as a monomer, regardless of the aggregation number in solution. This result occurs owing to the strength of monomer-surface and monomer-monomer interactions. If monomer-surface interactions are favored, the MB dimer adsorbs in the monomeric form. If monomer-monomer interactions are favored, dimer adsorption may occur. The visible spectra of adsorbed molecules indicated that MB was present at the surface as a mixture of monomeric and dimeric species. These results suggest that dimers are formed in the contact region between two aggregating particles.

Type
Research Article
Copyright
Copyright © 2001, The Clay Minerals Society

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References

Adamson, A.W., 1976 Physical Chemistry of Surfaces. New York Wiley-Interscience.Google Scholar
Bergmann, K. and O’Konski, C.T., 1963 A spectroscopic study of methylene blue monomer, dimer and complexes with montmorillonite Journal of Physical Chemistry 67 21692177 10.1021/j100804a048.CrossRefGoogle Scholar
Boutton, C. Kauranen, M. Persoons, A. Keung, M.P. Katrien, Y.J. and Schoonheydt, R.A., 1997 Enhanced second-order optical nonlinearity of dye molecules adsorbed onto Laponite particles Clays and Clay Minerals 45 483485 10.1346/CCMN.1997.0450318.CrossRefGoogle Scholar
Brina, R. and De Battisti, A., 1987 Determination of specific surface area of solids by means of adsorption data Journal of Chemical Education 64 175176 10.1021/ed064p175.CrossRefGoogle Scholar
Bujdák, J. and Komadel, P., 1997 Interaction of methylene blue with reduced charge montmorillonite Journal of Physical Chemistry B 101 90659068 10.1021/jp9718515.CrossRefGoogle Scholar
Carter, D.L. Heilman, M.D. and Gonzales, C.L., 1965 Ethylene glycol monoethyl ether for determining surface area of silicate minerals Soil Science 100 356360 10.1097/00010694-196511000-00011.CrossRefGoogle Scholar
Garfinkel-Shweky, D. and Yariv, S., 1997 The determination of surface basicity of the oxygen planes of expanding clay minerals by acridine orange Journal of Colloids and Interface Science 188 168175 10.1006/jcis.1996.4712.CrossRefGoogle Scholar
Grauer, Z. Grauer, G.L. Avnir, D. and Yariv, S., 1987 Metachromasy in clay minerals. Sorption of pyronin Y by montmorillonite and Laponite Journal of the Chemical Society Faraday Transactions I 83 16851701 10.1039/f19878301685.CrossRefGoogle Scholar
Helmy, A.K. Ferreiro, E.A. and de Bussetti, S.G., 1999 Surface area evaluation of montmorillonite Journal of Colloids and Interface Science 210 167171 10.1006/jcis.1998.5930.CrossRefGoogle ScholarPubMed
Jacobs, K.I. and Schoonheydt, R.A., 1999 Spectroscopy of methylene blue-smectite suspensions Journal of Colloids and Interface Science 220 103111 10.1006/jcis.1999.6513.CrossRefGoogle ScholarPubMed
Koopal, L.K., 1978 Influence of polymer adsorption from electrical double layer measurements. The silver iodide-polyvinyl alcohol system The Netherlands Agricultural University of Wageningen.Google Scholar
Lyklema, J., 1995 Fundamentals of interface and colloid science. Volume: Solid-liquid interfaces. London Academic Press.Google Scholar
Margulies, L. Rozen, H. and Nir, S., 1988 Model for competitive adsorption of organic cations on clays Clays and Clay Minerals 36 270276 10.1346/CCMN.1988.0360309.CrossRefGoogle Scholar
Potgieter, J.H., 1991 Adsorption of methylene blue on activated carbon. An experiment illustrating both the Langmuir and Freundlich isotherms Journal of Chemical Education 68 349350 10.1021/ed068p349.CrossRefGoogle Scholar
Rytwo, G. Nir, S. Margulies, L. Casal, B. Merino, J. Ruiz-Hitzky, E. and Serratosa, J.M., 1998 Adsorption of monovalent organic cations on sepiolite: Experimental results and model calculations Clays and Clay Minerals 46 340348 10.1346/CCMN.1998.0460313.CrossRefGoogle Scholar
Schulthess, C.P. and Dey, D.K., 1996 Estimation of the Langmuir constants using linear and nonlinear least squares regression analyses Soil Science Society of the America Journal 60 433442 10.2136/sssaj1996.03615995006000020014x.CrossRefGoogle Scholar
Spencer, W. and Sutter, J.R., 1979 Kinetics study of the monomer-dimer equilibrium of methylene blue in aqueous solution Journal of Physical Chemistry 83 15731576 10.1021/j100475a004.CrossRefGoogle Scholar
Van den Hul, H.J. and Lyklema, J., 1968 Determination of specific surface areas of dispersed materials. Comparison of the negative adsorption method with some other methods Journal of the American Chemical Society 90 30103015 10.1021/ja01014a003.CrossRefGoogle Scholar
Velasco, M.I. and De Pauli, C.P., 1993 Surface charge properties of an Haplustoll from Argentina Geoderma 59 345351 10.1016/0016-7061(93)90078-Y.CrossRefGoogle Scholar