| Title | Visible-spectroscopy study of the adsorption of alizarinate by Al-montmorillonite in aqueous suspensions and in solid state. | | Author(s) | Epstein M, Yariv S | | Institution | Tel-Hai Technological College, Upper Galilee 12210, Israel. | | Source | J Colloid Interface Sci 2003 Jul 15; 263(2):377-85. | | MeSH | Adsorption
Aluminum
Anthraquinones
Bentonite
Biophysics
Coloring Agents
Hydrogen-Ion Concentration
Magnesium
Models, Chemical
Models, Statistical
Silicon Dioxide
Sodium
Spectrometry, X-Ray Emission
Spectrophotometry
Temperature
Water
| | Abstract | The adsorption of the monovalent anionic dye alizarinate onto Na- and Al-montmorillonite was carried out by adding the dye into aqueous clay suspensions. Electronic spectra of aqueous suspensions and of air-dried dye-clay complexes were studied. Na-montmorillonite adsorbed only part of the added dye. With total amount of alizarinate up to 5 mmol dye per 100 g clay the adsorption of the dye takes place on the broken bonds, leading to peptization of the clay. Al-montmorillonite adsorbed alizarinate completely up to 10 mmol per 100 g clay. Above this loading there was a partition of the dye between the clay and the supernatant. The maximum adsorption for Na- and Al-clay was 4 and 25 mmol dye per 100 g clay, respectively. Absorption bands in the spectrum of Al-montmorillonite suspensions (488-504 nm) appear at longer wavelengths than in the spectrum of air-dried Al-montmorillonite (415-455 nm). Thermo-X-ray study of these clay-alizarinate complexes suggests that the organic compound was located in the interlayer space in Al-montmorillonite but was not located there in Na-montmorillonite. In Al-montmorillonite alizarinate formed a coordination complex with exchangeable Al(3+). In Na-montmorillonite it formed bonds with Al exposed on the broken-bonds sites. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 12909026 |
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