Preparation of magnetic polymeric composite nanoparticles by seeded emulsion polymerization

Seeded emulsion polymerization was used to prepare magnetic polymeric composite nanoparticles (MPCNPs) with the aim to Successfully encapsulate magnetite particles and to improve particle size distribution (PSD). Microscopical morphology and number-average diameter of hydrophilic magnetite particles (HMPs), magnetic seed latex nanoparticles (MSLNPs) and MPCNPs were observed and analyzed by transmission electron microscope (TEM). Weight-average diameter and PSD of MSLNPs and MPCNPs were also analyzed by TEM. Magnetic properties of MPCNPs were investigated by Vibrating Sample Magnetometry (VSM). The results showed that the encapsulation of magnetite particles was not complete by conventional emulsion polymerization but very successful by seeded emulsion polymerization. the resulted MPCNPs were nanoparticles with much narrower PSD than that of MSLNPs, and exhibited superparamagnetism and possessed a certain level of magnetic response. (c) 2009 Elsevier B.V. All rights reserved.