Study of the ferrofluid drying process for morphological and nanostructutal characterization

A drying method suitable for the study of the morphological and structural properties of colloidal magnetic systems, including a contrast agent used in Magnetic Resonance Imaging (MRI) is described. We tested three alternative ferrofluid drying methods: drying at 70 70ºCC in nitrogen atmosphere; drying in air at 70 70ºCC; and drying by liophylization using an MRI marker in the form of a colloidal suspension (EndoremTM - Guebert). X-ray diffraction (XRD), and transmission electron microscopy (TEM) were applied to each characterization method. The XRD allowed the observation of the possible physical-chemical changes of the stabilizers and also Fe3O4 present in the system. The morphology and nanoparticles size distribution was analyzed by TEM. Among the drying methods examined in this study, the liophylization has shown to be the more adequate one for the nanoparticles (Fe3O4) morphological study and nanostructural characterization, because the structure of the nanoparticles was maintained the same as in the suspension. The drying procedures performed at 70 70ºCC in the atmospheres of nitrogen and air let to the coalescence and growth of the nanoparticles, as well as some degradation has been noticed in some of the stabilizers.

Saved in:
Bibliographic Details
Main Authors: Gamarra,L. F., Brito,G. E. S. ., Pontuschka,W. M., Mamani,J. B., Moreira-Filho,C. A., Amaro Jr.,E.
Format: Digital revista
Language:English
Published: Sociedade Brasileira de Física 2007
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332007000800016
Tags: Add Tag
No Tags, Be the first to tag this record!