Zdrojový dokument:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 20/2014
ISSN:1211-5541
Abstrakt:
The oxidation of ferrous sulfate in aqueous medium was used to prepare
hydrophilic nanoparticles of Fe3O4 with the hydrodynamic size of 114 ± 59 nm. By
means of sol-gel method, the nanoparticles were coated with a layer of amorphous
SiO2, which provided the Fe3O4@SiO2 nanoparticles with the size of 188 ± 36 nm.
The reaction of Fe3O4@SiO2 with 3-aminopropyltriethoxysilane resulted in
attaching of amino groups to the surface of the particles. During the reaction
lasting 1 hour, the original size of particles (190 ± 40 nm) remained unchanged,
and the total nitrogen content was 2.21 %, and the nitrogen content corresponding
to reactive amino groups was 1.22 %. A prolongation of the reaction time up to 3 hours resulted in production of aggregates and increase in the total nitrogen
content up to 3.75 %. However, the content of reactive nitrogen increased only
negligibly (1.30 %). The spherical shape of the Fe3O4@SiO2–NH2 particles
produced and their hydrodynamic size are suitable for applications to catalysis
as well as for biomedical applications.