Magnetic response of CoFeO nanoparticles confined in a PNIPAM microgel network.

The paper addresses coupling of magnetic nanoparticles (MNPs) with the polymer matrix of temperature-sensitive microgels and their response to magnetic fields. Therefore, CoFeO@CA (CA = citric acid) NPs are embedded within -isopropylacrylamid (NIPAM) based microgels. The volume phase transition (VPT) of the magnetic microgels and the respective pure microgels is studied by dynamic light scattering and electrophoretic mobility measurements.

Goethite Nanorods: Synthesis and Investigation of the Size Effect on Their Orientation within a Magnetic Field by SAXS.

Goethite is a naturally anisotropic, antiferromagnetic iron oxide. Following its atomic structure, crystals grow into a fine needle shape that has interesting properties in a magnetic field. The needles align parallel to weak magnetic fields and perpendicular when subjected to high fields.

Distribution of CoFeO Nanoparticles Inside PNIPAM-Based Microgels of Different Cross-linker Distributions.

The aim of this study is to tailor the inner structure of positively charged poly-( N-isopropylacrylamid- co-allylamine) (P(NIPAM- co-AA)) microgels for a better control of the distribution of negatively charged magnetic cobaltferrite (CoFeO@CA) nanoparticles (MNPs) within the microgels. Therefore, two different strategies are followed for the microgel synthesis: the (one pot) batch method which leads to a higher cross-linker density in the microgel core and the feeding method which compensates different reaction kinetics of the cross-linker and the monomers. The latter one is expected to result in a homogeneous cross-linker distribution.

Tuning the Size of Thermoresponsive Poly(N-Isopropyl Acrylamide) Grafted Silica Microgels.

Core-shell microgels were synthesized via a free radical emulsion polymerization of thermoresponsive poly-(-isopropyl acrylamide), pNipam, on the surface of silica nanoparticles. Pure pNipam microgels have a lower critical solution temperature (LCST) of about 32 °C. The LCST varies slightly with the crosslinker density used to stabilize the gel network.