US Patent 8404347 Method of synthesis of amphiphilic magnetic composite particles

Amphiphilic, magnetic composite particles are comprised of cores and shells. The core contains both hydrophobic vinylic graft copolymer, hydrophobic vinylic homopolymer and magnetic nanoparticles, and the shell to which the hydrophobic vinylic polymer is grafted is a hydrophilic, nitrogen-containing polymer. Typically, the composite particles are made by a process which involves generating radicals on nitrogen atoms of the water-soluble polymer, and then initiating free-radical copolymerization of said vinylic monomer(s) and vinylic-coated magnetic nanoparticles, whereby vinylic polymer(s) undergo(es) phase separation and the vinylic coated magnetic nanoparticles are encapsulated within the vinylic polymer to form a composite latex.