Synthesis and thermo-XRD-analysis of the organo-clay color pigment
| Autor: | S. Yariv, Z. Yermiyahu, Isaak Lapides |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
inorganic chemicals
Thermal treatment Condensed Matter Physics Chloride chemistry.chemical_compound Pigment Montmorillonite Adsorption chemistry visual_art visual_art.visual_art_medium medicine Organic chemistry Amine gas treating Ammonium Physical and Theoretical Chemistry Thermal analysis Nuclear chemistry medicine.drug |
| Zdroj: | Journal of Thermal Analysis and Calorimetry. 88:795-800 |
| ISSN: | 1572-8943 1388-6150 |
| DOI: | 10.1007/s10973-006-8121-1 |
| Popis: | An intense blue organo-clay color pigment was obtained by adding naphthyl-1-ammonium chloride to a Na-montmorillonite aqueous suspension followed by treatment with sodium nitrite. This treatment resulted in the synthesis of the azo dye 4-(1-naphthylazo)-1-naphthylamine adsorbed onto the clay. The pigment was subjected to thermo-XRD-analysis and the diffractograms were curve-fitted. Heating naphthylammonium-montmorillonite at 360°C resulted in the evolution of the amine at temperatures lower than those required for the formation of charcoal and consequently the clay collapsed. On the other hand, heating the pigment at 360°C resulted in the conversion of the adsorbed azo dye into charcoal. The clay did not collapse, thus proving that the azo dye was located inside the interlayer space. Before the thermal treatment a short basal spacing in the pigment compared with that in the ammonium clay (1.28 and 1.35 nm, respectively) indicated stronger surface π interactions between the clayey O-plane and the azo dye than between this plane and naphthylammonium cation. The amount of dye after one aging-day of the synthesis-suspension increased with [NaNO2]/[C10H7NH3] ratio but did not increase with naphthylammonium when the [NaNO2]/[C10H7NH3] ratio remained 1. After 7 and 56 aging days it decreased, indicating that some of the dye decomposed during aging. |
| Databáze: | OpenAIRE |
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