One-step low-temperature synthesis of akaganeite and maghemite magnetic nanoparticles

A facile approach to the preparation of magnetic nanoparticles based on the oxide or oxide-hydroxide of chemically inert iron species (Fe3+ ions) stabilized with a polymer shell was proposed. The polymer matrices used for this purpose were the macromolecules of sodium alginate, a natural anionic polysaccharide, and a synthetic polymer preliminarily converted to microgel using N-bis-isopropylacrylamide containing polyacrylic acid (PAA) units. When sodium alginate is used for stabilization, iron oxide nanoparticles (maghemite) are formed, while in the presence of PAA-containing microgels, iron oxide-hydroxide nanoparticles (akageneite) are obtained.