Abstract:
Manganese oxide particles and lithium manganese oxide particles have been produced with an average diameter less than about 500 nm. The particles have a high degree of uniformity including a very narrow distribution of particles sizes. Methods are described for producing metal oxides by performing a reaction with an aerosol including a metal precursor. In particular, the particles can be formed by laser pyrolysis. The lithium manganese oxide particles can be formed by the heat treatment of nanoparticles of manganese oxide. Alternatively, lithium manganese oxide particles can be formed direct ly by laser pyrolysis. The lithium manganese oxide particles are useful as acti ve materials in the positive electrodes of lithium based batteries. Improved batteries result from the use of the uniform nanoscale lithium manganese oxi de particles.
Abstract:
A particle collection apparatus has a chamber, one or more filters and a back pressure system. The filters are located in the flow path through the system to collect the particles from an input gas stream. The back pressure system applies a pulse of gas against the flow through the system to dislodge particles collected on the filters. The dislodged particles fall to a particle drain where they are removed from the system. The particle collection apparatus can be connected to a particle synthesis apparatus. The particle collection apparatus and the particle synthesis apparatus can operated at reduced pressures.
Abstract:
Improvements to chemical reaction systems (100) provide for the production of commercial quantities of chemical products, such as chemical powders. The improved chemical reaction systems (100) can accomodate a large reactant flux for the production of significant amounts of product. Preferred reaction systems (100) are based on laser pyrolysis. Features of the system (100) provide for the production of highly uniform product particles.
Abstract:
Light reactive deposition uses an intense light beam to form particles that are directly coated onto a substrate surface. In some embodiments, a coating apparatus comprising a noncircular reactant inlet, optical elements forming a light path, a first substrate, and a motor connected to the apparatus. The reactant inlet defines a reactant stream path. The light path intersects the reactant stream path at a reaction zone with a product stream path continuing from the reaction zone. The substrate intersects the product stream path. Also, operation of the motor moves the first substrate relative to the product stream. Various broad methods are described for using light driven chemical reactions to produce efficiently highly uniform coatings.
Abstract:
Nanoscale particles, particle coatings/particle arrays and corresponding consolidated materials are described based on an ability to vary the composition involving a wide range of metal and/or metalloid elements and corresponding compositions. In particular, metalloid oxides and metal-metalloid compositions are described in the form of improved nanoscale particles and coatings formed from the nanoscale particles. Compositions comprising rare earth metals and dopants/additives with rare earth metals are described. Complex compositions with a range of host compositions and dopants/additives can be formed using the approaches described herein. The particle coating can take the form of particle arrays that range from collections of disbursable primary particles to fused networks of primary particles forming channels that reflect the nanoscale of the primary particles. Suitable materials for optical applications are described along with some optical devices of interest.
Abstract:
Improved reaction chamber designs are described that provide for improved control over the flow within the reaction chamber. The reaction chambers contain reactions for particle production from a flowing reactant stream. Improved reactant delivery nozzles are described that are useful for the delivery of gas/vapor reactants and/or aerosol reactants. Improved nozzle designs can result in more uniform reactant flow. Suitable reactors can comprise an electromagnetic radiation source that projects through the reactor to drive the reaction at an electromagnetic radiation reaction zone. The improved nozzle features are suitable for reactors for particle collection and/or for coating of substrates within the reaction chamber.
Abstract:
An aerosol delivery apparatus (96) is used to deliver an aerosol into a reaction chamber (92) for chemical reaction to produce reaction products suc h as nanoparticles. A variety of improved aerosol delivery approaches provide for the production of more uniform reaction products. In preferred embodiments, a reaction chamber (92) is used that has a cross section perpendicular to the flow of reactant having a dimension along a major axis greater than a dimension along a minor axis. The aerosol preferably is elongated along the major axis of the reaction chamber.
Abstract:
Vanadium oxide nanoparticles with different vanadium oxidation states and different crystal structures. The particles have a narrow distribution of particle diameters and unique properties that result from their small size and correspondingly large surface area. The particles are produced by laser pyrolysis, and can be further treated to change their properties, without destroying their nanoscale size. The stoichiometry and crystal structure can be varied by initial heating under mild conditions. The materials may be used as cathode active materials in high energy density batteries.
Abstract:
Light reactive deposition uses an intense light beam (684) to form particles that are directly coated onto a substrate (680) surface. In some embodiments, a coating apparatus comprising a noncircular reactant inlet (682), optical elements forming a light path (684), a first substrate (680), and a motor connected to the apparatus. The reactant inlet (682) defines a reaction zone with a product stream path continuing from the reaction zone. The substrate (680) intersects the product stream path. Also, operation of the motor moves the first substrate (680) relative to the product stream. Various broad methods are described for using light driven chemical reactions to produce efficiently highly uniform coatings.