Sodium polyacrylate modified Fe3O4 magnetic microspheres formed by self-assembly of nanocrystals and their applications

Sodium polyacrylate modified Fe3O4 magnetic microspheres (SPMFMs) formed by self-assembly of nanocrystals were synthesized by a solvothermal method in mixed solvents of ethylene glycol and water. The SPMFMs exhibited a quasi-superparamagnetic behavior, and the saturation magnetization reached as high as 81.6 emu/g. The potential applications of the SPMFMs in the magnetic resonance imaging (MRI), drug delivery and waste water treatment were investigated. The loading capacity of the SPMFMs for bovine hemoglobin was 95 mg/g, and 33% of the loaded bovine hemoglobin was released in a period of 75 h. The adsorption for methylene blue and fuchsin basic using the SPMFMs as the adsorbent in the waste water treatment was efficient and rapid (within 1 min). The SPMFMs after the adsorption of the organic pollutants could be recycled and reused effectively with a slightly reduced adsorption capacity.