| 摘要 |
A process for preparation of superparamagnetic hollow spherical nanostructures characterised in that Fe2+/Fe3+ ions are absorbed onto the surface solid silicon dioxide (SiO2) cores pre-prepared by the Stober process, after which the silicon dioxide cores are dissolved using alkaline aqueous solutions of [2OH-/ HCO3-] ions and [CO32-/HCO3-] ions having pH value between 7 and 12, and that the Fe2+/Fe3+ ions in the form of superparamagnetic spinel iron oxide nanoparticles are precipitated with a precipitating reagent. The silicon dioxide cores may be suspended in distilled water so that their concentration is 0.25-2.0 mol% and this suspension in the volume percentage between 0.1 and 0.5 is added to an aqueous solution of Fe2+/Fe3+ ions with molar concentration of 0.2-0.15 mol/L and wherein the aqueous solutions of iron salts are based on nitrates, sulphates, chlorides and acetates. |
