Nanoparticle based systems with one or more polymer phases attached have potential use in a wide range of applications, from nanometer-scale drug delivery to nanoparticle self-assembly for display and data storage to flow control in microfluidic devices. Here, polymer-metal nanocomposites, with one or two distinct polymer phases, were formed by a sequential synthesis: (1) particle retention on a solid substrate, (2) controlled radical polymerization, (3) particle release, and (4) an optional second back-fill polymerization. Fe3O4 was used as the core with polymer grafted in either a partial or complete shell. For the monophasic assembly, only one hemisphere of the nanoparticle has a grafted polymer. For the biphasic assembly, two chemically dissimilar polymers are grafted on separate hemispheres of the nanoparticle surface. The two polymers examined are responsive to pH (poly (methacrylic acid), PMAA) and temperature changes (poly (N-isopropyl acrylamide), PNIPAM). Thus, evaluation of the mobility and surface charge under different aqueous conditions becomes critical for future applications in in situ applications.  Significant differences were observed due to the macromolecular structure, chemical and physical (a)symmetry, and nano/micro-structural conformation. A systematic study is presented to determine the effects of the chemical functionality and macromolecular structure on the isoelectric point, zeta potential, mobility and hydrodynamic diameter of the nanocomposite system. Molecular weight, pH, temperature and ionic strength are the environmental conditions that are compared for these systems.

Electrophoretic mobility measurements of polymer-magnetic nanoparticle systems

247th National Meeting (2014)

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