Synthetic process to control the total size and component distribution of multilayer magnetic composite particles

Superparamagnetic Latex via Inverse Emulsion Polymerization

“…Recipes for the creation of monodisperse polymer latex and microspheres exist; heterocoagulation of nanoparticles (17)(18)(19) or the direct precipitation of magnetic materials (20)(21)(22) onto the surfaces of monosized latex results in magnetic latex, monodisperse in size. Further polymerization of a polymer layer to cap the latex surface creates hydrophobic (18) or hydrophilic (23) magnetic latex. Most often, such latex contains only small loadings of magnetic material; however, up to 24 wt% (6 vol%) magnetite has been demonstrated (23).…”

Stability in Colloidal Mixtures Containing Particles with a Large Disparity in Size

“…Furusawa et al (23)(24)(25) have investigated which are the most suitable conditions (i.e., pH of the dispersion medium, the particle concentrations and size ratio, mixing conditions) to prepare regular composite particles consisting of "core" large polymer particles, each surrounded by a "shell" of adsorbed small inorganic particles. The composite "raspberry-like" particles produced were further subjected to encapsulation (24) into a polymer layer, obtained via emulsion polymerization.…”

Proton Adsorption onto Alumina: Extension of Multisite Complexation (MUSIC) Theory

“…Electrophoresis measurements of high-purity ␣-alumina powders confirmed their IEP's at pH 3.3 to 4.8 in 10 Ϫ3 M KNO 3 aqueous solutions (28). Also, magnetic fine powder (NiO ⅐ ZnO ⅐ Fe 2 O 3 ) showed a similar tendency of a low IEP (29). Since all these samples were redispersed in water from dry powder states, it is possible that the number of oxo groups might have increased in the calcination step of the production.…”