A process for the production of nanoparticles from a liquid mixture comprising at least one precursor and at least one solvent in a reactor with continuous through-flow comprises the steps of feeding at least one oxygen-containing gas inflow stream having a temperature into the at least one reactor, adding at least one fuel having a temperature to the oxygen-containing gas inflow stream, wherein the fuel and the oxygen-containing gas inflow stream form a homogeneous ignitable mixture having a temperature, wherein the temperature of the homogeneous ignitable mixture is above the autoignition temperature of the homogeneous ignitable mixture, introducing at least one precursor-solvent mixture into the homogeneous ignitable mixture; autoignition of the ignitable mixture of oxygen-containing gas and fuel after an ignition delay time to form a stabilized flame and reacting the precursor-solvent mixture in the stabilized flame to form nanoparticles from the metal salt precursor, removing the formed nanoparticles.

[Problem]

A novel method for producing a nanoparticle having a metal particle which contains iron oxide to which one or more hydrophilic ligands are coordination bonded is provided, where the nanoparticle is useful as a contrast agent for magnetic resonance imaging.

[Means for Solution]

As the novel method for producing a nanoparticle having a metal particle which contains iron oxide to which one or more hydrophilic ligands are coordination bonded, by performing ligand exchange to a hydrophilic ligand from an iron oxide nanoparticle having a surface to which a hydrophobic ligand is coordination bonded in one step using a phase transfer catalyst, it is possible to expect shortening of production processes and reduction of hydrophilic ligands used.

Furthermore, by producing an iron oxide nanoparticle having a surface to which a hydrophobic ligand is coordination bonded using a dropwise addition method, it is possible to avoid a rapid temperature rise and a reaction at a high temperature of 200° C. or higher, which is more advantageous for industrial production.

[Problem]

A novel method for producing a nanoparticle having a metal particle which contains iron oxide to which one or more hydrophilic ligands are coordination bonded is provided, where the nanoparticle is useful as a contrast agent for magnetic resonance imaging.

[Means for Solution]

As the novel method for producing a nanoparticle having a metal particle which contains iron oxide to which one or more hydrophilic ligands are coordination bonded, by performing ligand exchange to a hydrophilic ligand from an iron oxide nanoparticle having a surface to which a hydrophobic ligand is coordination bonded in one step using a phase transfer catalyst, it is possible to expect shortening of production processes and reduction of hydrophilic ligands used.

Furthermore, by producing an iron oxide nanoparticle having a surface to which a hydrophobic ligand is coordination bonded using a dropwise addition method, it is possible to avoid a rapid temperature rise and a reaction at a high temperature of 200° C. or higher, which is more advantageous for industrial production.

An iron-based oxide magnetic powder has good thermal stability and a small change in coercive force even in a high-temperature environment and is one composed of particles of ε-iron oxide in which Fe sites are partially substituted by another metal element. A production method for such an iron-based oxide magnetic powder includes allowing a phosphorus-containing ion to coexist when a precipitate of an iron hydroxide containing a substituent metal element produced by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites is coated with silicon oxide using a silane compound.

An iron-based oxide magnetic powder has good thermal stability and a small change in coercive force even in a high-temperature environment and is one composed of particles of ε-iron oxide in which Fe sites are partially substituted by another metal element. A production method for such an iron-based oxide magnetic powder includes allowing a phosphorus-containing ion to coexist when a precipitate of an iron hydroxide containing a substituent metal element produced by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites is coated with silicon oxide using a silane compound.

A substitution-type ε-iron oxide magnetic particle powder having a reduced content of a non-magnetic α-type iron-based oxide and Fe sites of ε-Fe.sub.2O.sub.3 partially substituted by another metal element is obtained by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites to a pH of 2.0 or higher and 7.0 or lower. A silicon compound having a hydrolyzable group is added to a dispersion liquid containing an iron oxyhydroxide having a substituent metal element or a mixture of an iron oxyhydroxide and a hydroxide of a substituent metal element. The dispersion liquid is neutralized to a pH of 8.0 or higher and the iron oxyhydroxide having a substituent metal element or the mixture of the iron oxyhydroxide and the hydroxide of a substituent metal element is coated with a chemical reaction product of the silicon compound and then heated.

A method for producing crystalline α-Fe2O3 nanoparticles involving ultrasonic treatment of a solution of an iron (III)-containing precursor and an extract from the seeds of a plant in the family Linaceae. The method involves preparing an aqueous extract from the seeds of a plant in the family Linacae and dropwise addition of the extract to the solution of an iron (III)-containing precursor. The method yields crystalline nanoparticles of α-Fe.sub.2O.sub.3 having a spherical morphology with a diameter of 100 nm to 300 nm, a mean surface area of 240 to 250 m.sup.2/g, and a type-II nitrogen adsorption-desorption BET isotherm with a H3 hysteresis loop. A method for the photocatalytic decomposition of organic pollutants using the nanoparticles is disclosed. An antibacterial composition containing the crystalline α-Fe.sub.2O.sub.3 nanoparticles is also disclosed.

The present invention belongs to the technical field of petroleum processing, and specifically relates to a method for preparing a catalyst for inferior residual oil suspended bed hydrocracking. Using sol-gel method and hydrothermal method, a mesoporous γ-Fe.sub.2O.sub.3 catalyst suitable for inferior residual oil suspended bed hydrocracking with a high specific surface area was prepared, based on FeCl.sub.3.6H.sub.2O, Fe.sub.2(SO.sub.4).sub.3.xH.sub.2O as inorganic iron source, and cheap sawdust powder as template. The present invention proposes to prepare a γ-Fe.sub.2O.sub.3 material with a mesoporous structure, a high specific surface area and a high pore volume using cheap raw materials and a simple and green synthesis process. The material as a catalyst has a good application effect in the heavy oil suspended bed hydrocracking reaction with a small amount, therefore having good commercial and industrial application value.

The present invention belongs to the technical field of petroleum processing, and specifically relates to a method for preparing a catalyst for inferior residual oil suspended bed hydrocracking. Using sol-gel method and hydrothermal method, a mesoporous γ-Fe.sub.2O.sub.3 catalyst suitable for inferior residual oil suspended bed hydrocracking with a high specific surface area was prepared, based on FeCl.sub.3.6H.sub.2O, Fe.sub.2(SO.sub.4).sub.3.xH.sub.2O as inorganic iron source, and cheap sawdust powder as template. The present invention proposes to prepare a γ-Fe.sub.2O.sub.3 material with a mesoporous structure, a high specific surface area and a high pore volume using cheap raw materials and a simple and green synthesis process. The material as a catalyst has a good application effect in the heavy oil suspended bed hydrocracking reaction with a small amount, therefore having good commercial and industrial application value.

Magnetic beads comprise a plurality of magnetic nanoparticles, dispersed in a non-magnetic matrix. The magnetic beads have an average particle size of 0.1 μm to 100 μm. The matrix may comprise an inorganic metal oxide or a polymer. The magnetic beads have a specific surface area of at least 40 m.sup.2/g.