The sol-gel method was used to prepare iron oxide-silica nanocomposite materials. Different drying conditions were used in order to obtain aerogel and xerogel materials. The samples were characterized by thermal analysis, X-ray diffraction (XRD), N-2-physisorption and transmission electron microscopy (TEM) techniques. Aerogel samples have a much higher surface area than the xerogel samples; moreover, different supercritical drying conditions give rise to a different porous structure. The stabilization of the maghemite phase in the xerogel nanocomposites depends on the iron content and it is more difficult in the aerogel samples. The early sol-gel preparation stages also play an important role. (C) 2001 Elsevier Science B.V. All rights reserved.
Iron oxide-silica aerogel and xerogel nanocomposite materials
CASULA, MARIA FRANCESCA;CORRIAS, ANNA;
2001-01-01
Abstract
The sol-gel method was used to prepare iron oxide-silica nanocomposite materials. Different drying conditions were used in order to obtain aerogel and xerogel materials. The samples were characterized by thermal analysis, X-ray diffraction (XRD), N-2-physisorption and transmission electron microscopy (TEM) techniques. Aerogel samples have a much higher surface area than the xerogel samples; moreover, different supercritical drying conditions give rise to a different porous structure. The stabilization of the maghemite phase in the xerogel nanocomposites depends on the iron content and it is more difficult in the aerogel samples. The early sol-gel preparation stages also play an important role. (C) 2001 Elsevier Science B.V. All rights reserved.I metadati presenti in IRIS UNICA sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono protetti da diritto d'autore, salvo diversa indicazione.



