The effect of heat treatment on the structure of kaolin and its in vitro hemolytic activity
| Autor: | J. Kis, J. Kabai, S. Mányai, M. Timár, Éva Süveges |
|---|---|
| Rok vydání: | 1970 |
| Předmět: |
Hot Temperature
Chemical Phenomena Surface Properties Mineralogy Mullite Crystal structure Hemolysis Biochemistry chemistry.chemical_compound Adsorption X-Ray Diffraction hemic and lymphatic diseases Specific surface area medicine Kaolinite Dehydration Kaolin General Environmental Science medicine.disease Cristobalite Methylene Blue Chemistry chemistry Aluminum Silicates Methylene blue Nuclear chemistry |
| Zdroj: | Environmental Research. 3:187-198 |
| ISSN: | 0013-9351 |
| DOI: | 10.1016/0013-9351(70)90015-0 |
| Popis: | Powders of water-cleaned white kaolin were heated at different temperatures (200, 350, 500, 650, 800, and 950°). Changes in the internal structure of kaolin (density and crystal structure) and surface properties (specific surface area, immersion heat, and methylene blue adsorption) were investigated and compared with alterations of the in vitro hemolytic effect—a model of cell damaging effect—of kaolin dusts. Complete dehydration of kaolinite crystals into metakaolinite between temperatures of 500 and 650° was accompanied by complete loss of hemolytic activity. When heating was carried out at higher temperatures, 800 or 950°, the hemolytic effect became more intensive again, as γ-Al 2 O 3 (or mullite) and SiO 2 (cristobalite) were formed from metakaolinite. Of the surface properties studied, only methylene blue adsorption was found to be directly correlated with the hemolytic activity. The extent of hemolysis caused by kaolin samples heated at different temperatures depended on the crystal structure and hydration of the surface. |
| Databáze: | OpenAIRE |
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