Natural nanoclays: applications and future trends – a Chilean perspective
| Autor: | María de la Luz Mora, M. Calabi Floody, B. K. G. Theng, P. Reyes |
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| Rok vydání: | 2009 |
| Předmět: |
010302 applied physics
Nanocomposite Chemistry Geochemistry Weathering 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Silicate chemistry.chemical_compound Montmorillonite Chemical engineering Geochemistry and Petrology Aluminosilicate 0103 physical sciences Water treatment 0210 nano-technology Allophane Clay minerals |
| Zdroj: | CLAY MINERALS Artículos CONICYT CONICYT Chile instacron:CONICYT |
| ISSN: | 1471-8030 0009-8558 |
| Popis: | Because of their large potential for agricultural, industrial and medicinal applications, nanomaterials have been the focus of much research during the past few decades. Nanoclays are natural nanomaterials that occur in the clay fraction of soil, among which montmorillonite and allophane are the most important species. Montmorillonite is a crystalline hydrous phyllosilicate (layer silicate). Organically-modified montmorillonites or ‘organoclays’, formed by intercalation of quaternary ammonium cations, have long been used as rheological modifiers and additives in paints, inks, greases and cosmetics and as carriers and delivery systems for the controlled release of drugs. Perhaps the largest single usage of organoclays over recent years has been in the manufacture of polymer-clay nanocomposites. These organic–inorganic hybrid materials show superior mechanical, thermal and gas-barrier properties. Organoclays are also useful in pollution control and water treatment. Allophane is a non-crystalline aluminosilicate derived from the weathering of volcanic ash. A large proportion of the agricultural land in Chile is covered by volcanic soils,the clay fraction of which is dominated by allophane. Consisting of nanosize (3.5–5.0 nm) hollow spherules, allophane is a suitable support material for enzyme immobilization. Allophane is also effective at adsorbing phenolic compounds and colour from kraft mill effluents and phosphate from water and wastewater. |
| Databáze: | OpenAIRE |
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