Formation of a three-dimensional microstructure of Fe3O4-poly(vinyl alcohol) composite by evaporating the hydrosol under a magnetic field

In this paper, we report on the self-assembly formation of three-dimensional microstructures of Fe3O4 hydrosol. First, we perform new, facile, and direct fabrication of a stable hydrosol of Fe3O4 nanoparticles, based on the sonolysis of an aqueous solution of iron acetate in the presence of PVA- 100 000. This is then followed by investigations of the formation of different microstructures obtained on drying a drop of the water suspension on a glass microscope substrate. The evaporation was carried out both without and in the presence of an external magnetic field.