Anisotropic Magnetic Polymeric Particles with a Controllable Structure via Seeded Emulsion Polymerization

Abstract

Magnetic polymer composites have been widely utilized in potential applications in material science, such as reduction of dyes, immunodiagnostics, biomedicals, and magnetically controllable photonic crystals owing to large surface areas, fast separation, and recyclable performance. In this work, anisotropic magnetic particles were prepared by seeded emulsion polymerization, with morphologies of "Fe 3 O 4 -shell", "hemisphere-like", "raspberry-like", "multiple lobes-like", and "sandwich-like". Poly-(styrene/divinylbenzene/mono-2-(methacryloxy)ethyl succinate) @ Fe 3 O 4 (P(St/DVB/MMES)@Fe 3 O 4 ) were the seed microspheres, and P(St/DVB/MMES)@Fe 3 O 4 @polymer particles are achieved by seeded emulsion polymerizations. The morphology of the particles depends on polymerization conditions (monomer ratios and surfactant), particle properties, and so on. Then, the minimum surface free energy change principles were used to predict the equilibrium morphologies of the magnetic polymer composites. Through theory, the model gives the correct tendency and good agreement with the equilibrium morphology which was in tandem with TEM results. Lastly, after in situ surface deposition of Ag nanoparticles, magnetic composite particles with sandwichlike morphology were applied for the catalytic degradation of 4-nitrophenol (4-NP) reacting with NaBH 4 . The apparent rate coefficient is 0.0069 s −1 , and it can keep mainly about 80% efficiency in catalysis after five cycles.

Facile “One-Pot” Fabrication of Dual-Functional Anisotropic Particles via Dispersion Polymerization for Adsorption of Copper Ions

“…Raspberry-like particles have highly rough surfaces, large specific surface areas, and superhydrophobic/hydrophilic interface; therefore, they are widely applied in several fields. Synthetic strategies for raspberry-like particles typically involve seeded polymerization, Pickering polymerization, formation of inorganic coronas on the core particles, and so on. Most of these synthesis strategies require the preparation of smaller particles (typically nano- or microscale) in advance as nuclei or corona for composite particles or clusters.…”