Comparative structure analysis of magnetic fluids at interface with silicon by neutron reflectometry

• The adsorption of surfactant coated magnetic nanoparticles from highly stable magnetic fluids on crystalline functionalized silicon is studied by neutron reflectometry. Two types of magnetic fluids based on nanomagnetite dispersed and stabilized in non-polar organic solvent (deuterated benzene) and strongly polar solvent (heavy water) are considered. In both cases the interface shows the formation of just one well-defined adsorption layer of nanoparticles, which is insensitive to the effect of the external magnetic field. Still, the particle concentration in the benzene-based fluid is higher in the vicinity to the silicon surface as compared to the bulk distribution. Despite the presence of an aggregate fraction in the water-based system the width of the adsorption layer is consistent with the size of separated particles, thus showing the preferable adsorption of non-aggregated particles.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

Magnetic fluids

Ferrofluids

Neutron reflectometry

Nanoparticles adsorption

Structure of layer

Publication and Content Type

ref (subject category)

art (subject category)