Preparation and characterization of magnetic composites based on a natural zeolite
GutiéRrez, Marlen (Center for the Development of Nanoscience and Nanotechnology. CEDENNA)
Escudey, Mauricio (Center for the Development of Nanoscience and Nanotechnology. CEDENNA)
Escrig, Juan (Center for the Development of Nanoscience and Nanotechnology. CEDENNA)
Denardin, Juliano C. (Center for the Development of Nanoscience and Nanotechnology. CEDENNA)
Altbir, Dora (Center for the Development of Nanoscience and Nanotechnology. CEDENNA)
Fabris, Jose D. (Universidade Federal de Minas Gerais. Departmento de Química)
Cavalcante, Luis C. D. (Universidade Federal de Minas Gerais. Departmento de Química)
García-GonzáLez, María Teresa (Consejo Superior de Investigaciones Científicas (Espanya). Instituto de Ciencias Agrarias)

Fecha:	2010
Resumen:	A magnetic composite was prepared by wet-impregnating a powder of a natural zeolite with a magnetic Fe oxide-containing synthetic material. Both starting materials were first characterized with X-ray diffraction, scanning electron microscopy, Mössbauer spectroscopy, and by isoelectric-point using vibrating-sample magnetometry. The synthetic Fe oxide-containing material was characterized as a mixture of magnetite (FeO) and goethite (α-FeOOH). From the Fe Mössbauer analysis, the relative subspectral area for magnetite corresponds to 93(2)%; the remaining spectrum is assignable to goethite. After the impregnation process, magnetite was still identified in the composite material as a magnetic layer surrounding the zeolite particles; no magnetically ordered goethite could be detected. The Mössbauer pattern for this sample indicates a much more complex structure than for the precursor material, based on Fe oxides, with some more altered magnetite and an intense central doublet of (super)paramagnetic Fe, probably due to small Fe (hydr)oxides and/or to a residual contribution of Fe-bearing species from the starting zeolite material. The composite preparation procedure also promoted the change of the characteristic A-type zeolite to mordenite. The resulting magnetic composite presented a magnetic coercivity of as much as 0. 140 A m, at 77 K. The final composite is now being evaluated as an adsorbent: results to date confirm that this novel magnetic material may have applications in the remediation of contaminated water bodies.
Ayudas:	Ministerio de Ciencia e Innovación AGL2005-07017-C03-03
Derechos:	Tots els drets reservats.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Coercivity ; Fe Oxide ; Isoelectric Point ; Magnetite ; Magnetic Zeolite ; Mössbauer ; Spectroscopy
Publicado en:	Clays and Clay Minerals, Vol. 58, Núm. 5 (2010) , p. 589-595, ISSN 1552-8367

DOI: 10.1346/CCMN.2010.0580501

7 p, 3.5 MB  Acceso restringido a la UAB

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