Clays and Clay Minerals, Vol. 58, No. 5, 589–595, 2010.
Loading...
Authors
Gutierrez, Marlen
Escudey, Mauricio
Escrig, Juan
Denardin, Juliano C.
Altbir, Dora
Fabris, Jose D.
Cavalcante, Luis C. D.
Garcia-gonzalez, Maria Teresa
Issue Date
2010
Type
Article
Language
Keywords
Periodicals , Geology , Coercivity , Fe Oxide , Isoelectric Point , Magnetite , Magnetic Zeolite , Mossbauer Spectroscopy
Alternative Title
Preparation And Characterization Of Magnetic Composites Based On A Natural Zeolite
Abstract
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, Mo¨ssbauer spectroscopy, and by isoelectric-point using vibrating-sample magnetometry. The synthetic Fe oxide-containing material was characterized as a mixture of magnetite (Fe3O4) and goethite (a-FeOOH). From the 57Fe Mo¨ssbauer 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 Mo¨ssbauer 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 Fe3+, 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-1, 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.
Description
gsccm58501-gut.pdf -- 1,439KB
Citation
Clays and Clay Minerals, Vol. 58, No. 5, 589–595, 2010.
Publisher
The Clay Minerals Society
License
Copyright © 2006-2018