In this contribution an original synthesis procedure of superparamagnetic photocatalytic nanocomposite particles was presented. The nanocomposite particles are composed of a core containing cluster of superparamagnetic nanoparticles covered with nanocrystalline anatase coating. The particles will be used for photocatalytic water purification, where the particle are dispersed in polluted water and after the purification magnetically separated and reused.
COBISS.SI-ID: 25969959
The size of nanoparticles is usually controlled with synthesis conditions and/or with the addition of surfactants. However, the synthesis of the exactly optimal particles with nano size showing, at the same time, applicable physical properties, still remains a challenge for many compounds. In this contribution we represent an alternative route for the particle-size control that is based on partial substitution of iron ions with the larger ions of scandium or indium. We showed that such substitutions, using hydrothermal synthesis, affects the nucleation rate and prevents secondary recrystallization of particles. Namely, the later results in exaggerated particle growth of barium ferrite. This procedure enables synthesis of nanoplates with diameters of 50-100 nm and thicknesses of 3-5 nm, which show applicable magnetic properties.
COBISS.SI-ID: 26308391
The influence of nanoparticles’ surface charge on their internalization into two types of cells in vitro was systematically studied. The iron-oxide nanoparticles, approximately 13 nm in size, were coated with thin silica layer. Onto the silica, silane molecules were grafted, having terminal amino groups (for positive surface charge) or terminal carboxyl groups (for negative charge). It appeared that the nanoparticles displaying positive surface charge enter cells in much higher extent.
Synthesis of CoFe2O4 nanoparticles using co-precipitation from aqueous solutions and hydrothermal synthesis was systematically studied in the presence of oleic acid. Oleic acid adsorbs onto the formed nanoparticles, increases spinel formation temperature and limits particle growth. The oleic-acid-coated nanoparticles can form colloidal suspensions even when their size is above superparamagnetic limit and they display ferrimagnetic properties.
COBISS.SI-ID: 25609511
This is the first contribution that represents a possibility to control interparticle interaction between cobalt ferrite nanoparticles under an applied magnetic field for the preparation of columnar microstructures. The unwanted magnetic attraction between the particles can be prevented in aqueous suspensions with electrostatic and hydration repulsion forces. The magnetic attraction between the nanoparticles was further controlled with an applied magnetic field, of suitable strength, in order to assemble the nanoparticles into dense columns. In such a way, cobalt ferrite columns with heights of several hundreds of microns were prepared and represent basis for the 1-3 type magneto-electrics.
COBISS.SI-ID: 26361383