Core-coil devices operate by electromagnetic induction and include inductors, transformers, and electromagnets. Cooled core-coil devices include a magnetic core having a channel through it, and a coil wound around the core. Cooled core-coil devices additionally include a coolant loop that carries ferrofluid coolant through the channel and forms a loop with the channel that extends outside the core. Ferrofluid coolant circulates in the loop without a pump due to a thermo-magnetic response to the device's thermal and magnetic field gradients and thereby cools the core while simultaneously adding to the device's inductance.

Embodiments of the present disclosure describe a magnetic substrate including a cured magnetic ink and a cured polymer resin, wherein the cured magnetic ink includes a plurality of functionalized magnetic iron oxide nanoparticles and wherein the magnetic substrate is a freestanding magnetic substrate.

The invention relates to a process for preparing a dispersion of magnetizable particles in polyol by mechanical mixing of the magnetizable particles at a temperature in the range of from 80 to 260 C., preferably 100 to 220 C., more preferably 160 to 200 C. with a polyol selected from the group consisting of polyesterols or polyether ester polyols having an acid number in the range of from 0.1 to 3.0.

A preparation method of a perfluoropolyether-based magnetic liquid includes dispersing magnetic nanoparticles coated with graphene oxide into a solution of N,N-dimethylformamide to obtain solution A; dispersing a surfactant into dichloromethane, and adding triethylamine as a cosolvent to obtain solution B; mixing the solution A and the solution B uniformly, heating them under reflux and stirring them for a modification reaction; and after the modification reaction is completed, washing and drying a reaction product to obtain the modified magnetic nanoparticles coated with the graphene oxide; dispersing the modified magnetic nanoparticles coated with the graphene oxide into a base carrier liquid to prepare the perfluoropolyether-based magnetic liquid. The surfactant is a perfluoroalkylamine. The base carrier liquid is a perfluoropolyether oil. The modification reaction is performed at a temperature of 50 to 120 C. for a time period of 20 to 50 hours.

A preparation method of a perfluoropolyether-based magnetic liquid includes dispersing magnetic nanoparticles coated with graphene oxide into a solution of N,N-dimethylformamide to obtain solution A; dispersing a surfactant into dichloromethane, and adding triethylamine as a cosolvent to obtain solution B; mixing the solution A and the solution B uniformly, heating them under reflux and stirring them for a modification reaction; and after the modification reaction is completed, washing and drying a reaction product to obtain the modified magnetic nanoparticles coated with the graphene oxide; dispersing the modified magnetic nanoparticles coated with the graphene oxide into a base carrier liquid to prepare the perfluoropolyether-based magnetic liquid. The surfactant is a perfluoroalkylamine. The base carrier liquid is a perfluoropolyether oil. The modification reaction is performed at a temperature of 50 to 120 C. for a time period of 20 to 50 hours.

A method for fabricating a thermal composite includes pouring a mixture including a plurality of magnetically susceptible particles and a thermosetting polymer into a mold, placing the mold containing the mixture in a chamber including a plurality of magnet arrays, and heating the mold containing the mixture in the chamber for a time and at a temperature sufficient to cure the thermosetting polymer. At least one of the plurality of magnet arrays includes a Halbach array.

It is an object of the present invention to provide a nanodispersion liquid of iron oxyhydroxide that is stable and does not contain components derived from auxiliary components. The nanodispersion liquid of iron oxyhydroxide according to the present invention is a nanodispersion liquid in which particles comprising iron oxyhydroxide as a main component and having an average particle diameter d50 of 0.2 m or less and a d90 of 1 m or less are dispersed in a solvent. The iron oxyhydroxide is preferably -iron oxyhydroxide. The nanodispersion liquid of iron oxyhydroxide according to the present invention preferably contains no other components than a substance derived from at least either of an iron compound and a base, a pH adjusting agent, and a solvent.

The present invention is in the field of fluids and the like comprising magnetic particles, such as ferromagnetic particles, anti-ferromagnetic particles, ferrimagnetic particles, synthetic magnetic particles, paramagnetic particles, superparamagnetic particles, such as magnetic fluids, a method of stabilizing magnetic particles, use of these fluids and functionalized particles. Such fluids have a large variety of applications, such as sealants, as a sensor, in biomedics, etc. The present invention is further directed to a method of obtaining a catalyst for use in the depolymerisation of polymers into oligomers and monomer.

An oil-based magnetic ink having an improved long-term storage stability is provided. The oil-based magnetic ink contains ferrite particles, a dispersant, a petroleum-based hydrocarbon solvent, a fatty acid ester-based solvent, and at least one selected from the group consisting of a glycol ether-based solvent and an alkanediol-based solvent, wherein the glycol ether-based solvent is a compound represented by R.sup.1O(R.sup.2O).sub.mH where R.sup.1 is an alkyl group having 4 to 8 carbon atoms, R.sup.2 is an alkylene group having 2 or 3 carbon atoms, and m is 3 or 4, and the alkanediol-based solvent is an alkanediol-based solvent having 6 to 10 carbon atoms.

A nanoparticle sized between 10-180 nm composed of M(III).sub.2O.sub.3, M(II)O and M(II)M(III).sub.2O.sub.4, wherein M(III) is a trivalent metal and M(II) is a divalent metal, or Fe.sub.2O.sub.3, MnO and M(II)O, wherein M is a divalent metal selected from the group consisting of Fe, Ni, Co, Cu, Pt, Au, Ag, Ba and a rare earth metal.