| Titre : | Sulfur pigments synthesized from zeolite LTA under vacuum and in Air. XRD and spectroscopic (UV−vis, FTIR, Raman, ESR, ESE) characterization (2010) |
| Auteurs : | Stanisław K. Hoffmann, Auteur ; Janina Goslar, Auteur ; Stefan Lijewski, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 49 N° 17, Septembre 1, 2010) |
| Article en page(s) : | pp 8192–8199 |
| Note générale : | Chimie industrielle |
| Langues : | Anglais |
| Tags : | Sulfur Zeolite Spectroscopic. |
| Résumé : | X-ray, UV−vis, FT-infrared, Raman, continuous wave, and pulsed ESR spectroscopy were applied to characterize pigments prepared at 500 °C under vacuum or in air from mixtures of zeolite A (LTA) with sulfur (40 wt %) and anhydrous sodium sulfide (Na2/S = 0.1−0.4). The samples maintained the LTA structure. Sample color results from an S3− absorption band and the shoulder of a UV band. The fingerprint and asymmetric stretch region of the IR spectra show that the pigments synthesized in air have more disordered structures. The S2−/S3−ratio was estimated from Raman spectra. The ESR spectra of S3− radicals show the existence of several phases visible as five different ESR components. Two components dominate: ideal [Na4S3−]3+ clusters and clusters existing in a disordered environment. The samples synthesized in air show a substantial distortion of local structure. Synthesis in vacuum leads to products containing about 20% of the ordered crystalline phase. |
| DEWEY : | 660 |
| ISSN : | 0888-5885 |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie100983m |
