USA As Represented by Secretary of the Navy

Virginia Commonwealth University

Chemtreat, Inc.

University of New Orleans Research and Technology Foundation, Inc.

Everett Earl Carpenter

Vincent Carpenter

John Richardson

Vincent G Harris

Lynn K Kurihara

Massimo F Bertino

Dale P Stuart

Ahmed A Farghaly

Shiv N Khanna

Shannon A Morrison

Charles J O'Connor

Zachary J Huba

Meichun Qian

Jessica Ann Sims

Kyler J Carroll

In various aspects, methods of making perovskite manganese oxide particles are provided as well as perovskite manganese oxide particles made therefrom. The perovskite manganese oxide particles exhibit a strong magnetocaloric effect, making them well suited for applications in power generation and magnetic refrigeration, especially at or near room temperature. The methods can include forming an aqueous mixture of (i) a low-molecular-weight polymeric polyalcohol gel precursor, (ii) a stoichiometric amount of metal salts or hydrates thereof, wherein the metal salts or hydrates thereof comprise at least a Manganese (Mn), and (iii) a polybasic carboxylic acid; polymerizing the aqueous mixture to form a gel containing perovskite manganese oxide nanoparticles entrapped therein; and calcining the gel to remove at least a portion of organic material in the gel and form the perovskite manganese oxide particles. Method and systems are also provided for power generation and magnetic refrigeration using the perovskite manganese oxide particles.

Perovskite manganese oxides with strong magnetocaloric effect and uses thereof

Continuous flow synthetic methods are used to make single phase magnetic metal alloy nanoparticles that do not contain rare earth metals. Soft and hard magnets made from the magnetic nanoparticles are used for a variety of purposes, e.g. in electric motors, communication devices, etc.

Non-rare earth magnetic nanoparticles

Disclosed are methods and apparatus for improving heat transfer of recirculating fluids within a system by introducing a ferrofluid in which iron oxide nanoparticles are suspended in a carrier fluid that is, in turn, added to a working fluid for increasing the heat capacity of the working fluid. The ferrofluid suspension can be prepared ex-situ and metered into the working fluid from a separate reservoir or may be prepared in-situ as needed through the use of an inline reactor. The ferrofluid can be introduced with other water treatment additives which are compatible with the colloidal suspension and monitored directly and/or indirectly for controlling the heat capacity performance of the system.

Method and apparatus for improving heat transfer in industrial water systems with ferrofluids

This invention comprises nanoparticles for use with biosensors. The nanoparticles have core/shell architecture. The nanoparticles can be detected by two means, magnetic and optical by virtue of the nanoparticles magnetic core and fluorescent semiconductor shell. Methods of making the nanoparticles and their composition are described.

Method for making magnetic fluorescent core shell nanoparticles

A method for making monodispersed magnetic nanoparticles of nickel zinc ferrite (NZFO) at room temperature by mixing together two micelle solutions. The first micelle solution comprises zinc, nickel, and iron metal salts; a surfactant; and a hydrocarbon. The second micelle solution comprises an aqueous hydroxide, a surfactant, and a hydrocarbon. After mixing the two micelle solutions, the ferrite precipitates.

Nanoparticle nickel zinc ferrites synthesized using reverse micelles

Fluorescent-magnetic nanoparticles with core-shell structure

A new low temperature method of reducing metallic salts, both inorganic and organic to metallic nanoparticles has been discovered. The reduction reaction is carried out in low boiling point monoalkylethers of ethylene glycol and mixtures of this solvent with alkane diols. Metallic nanoparticles are produced with size range of 1&#x2013;100 nm.

Low temperature synthesis of metallic nanoparticles

By utilizing the sequential synthesis afforded reverse micelles, nanocomposite materials can be synthesized which have a diamagnetic core surrounded by a thin shell of ferromagnetic material passivated with a second shell of a diamagnet. Using gold as the diamagnetic material and iron as the ferromagnetic material, nanocomposites can be synthesized where there is a thin layer of the magnetic material, which is passivated and protected from oxidation. In this case, all of the spins of the magnetic layer lie within the surface of the particle.

Growing community of inventors

Mechanicsville, VA, United States of America

Everett Earl Carpenter