Synthesis of binary polyelectrolyte/inorganic composite capsules of micron size

Different approaches for the synthesis of binary polyelectrolyte/inorganic layered composite capsules of micron size are described. As the polyelectrolyte part of the composite, a poly(styrene sulfonate)/poly(allylamine hydrochloride) complex was taken; the inorganic component was composed of magnetic nanoparticles (Fe₃O₄, CoFe₂O₄, MnFe₂O₄, ZnFe₂O₄), insulator nanoparticles (rare-earth fluorides) or metal nanoparticles (Ag). An inner inorganic layer was formed inside the hollow polyelectrolyte capsule via chemical or photochemical reaction in a spatially restricted capsule volume. The inorganic nanophase synthesized was characterized by transmission electron microscopy, scanning electron microscopy, and wide angle X-ray scattering techniques and weakly crystallized particles 6–9 nm in diameter were detected, presumably attached to the inner side of the capsule shell. Polyelectrolyte capsules filled with ferrite (magnetite) particles possess substantial magnetic activity and are easily manipulated in water solution by an external magnetic field.