Patent classifications
C01B32/984
Method of preparing silicon carbide and filters made therefrom
A method of making SiC nanowires comprising: (a) mixing silicon powder with a carbon-containing biopolymer and a catalyst at room temperature to form a mixture; and (b) heating said mixture to a pyrolyzing temperature sufficient to react said biopolymer and said silicon power to form SiC nanowires.
Silicon to silicon carbide conversion for ceramic matrix composite fabrication
Disclosed are techniques and methods for producing silicon carbide and ceramic matrix composites from hydrocarbons. In one aspect, a method includes preforming a shape using silicon carbide fibers placed into a chamber, evacuating the chamber causing a silicon and polymer slurry to enter the chamber, and pressurizing the chamber causing the silicon and polymer slurry to permeate the silicon carbide fibers. The method includes heating the chamber to cause pyrolysis of the polymer and a hydrocarbon passed into the chamber into carbon and hydrogen gas. The carbon from the pyrolyzed polymer and hydrocarbon provide a coating of carbon on the silicon in the silicon and polymer slurry. The method includes heating the chamber to a higher temperature causing the silicon to melt and react with the carbon to form silicon carbide. The formed silicon carbide and the silicon carbide fibers form the ceramic matrix composite.
Method for preparing ultrahigh-purity silicon carbide powder
The present invention relates to a method for preparing an ultrahigh-purity silicon carbide powder, more particularly to a method for preparing an ultrahigh-purity silicon carbide granular powder by preparing a gel wherein a silicon compound and a carbon compound are uniformly dispersed via a sol-gel process using a liquid state silicon compound and a solid or liquid state carbon compound of varying purities as raw materials, preparing a silicon dioxide-carbon (SiO.sub.2C) composite by pyrolyzing the prepared gel, preparing a silicon carbide-silicon dioxide-carbon (SiCSiO.sub.2C) composite powder via two-step carbothermal reduction of the prepared silicon dioxide-carbon composite, adding a silicon metal and then conducting carbonization and carbothermal reduction at the same time by heat treating, thereby growing the synthesized silicon carbide particle with an increased yield of the silicon carbide.
Cellular porous monoliths containing condensed tannins
A method for producing polyHIPE porous monoliths, of the polyHIPE type or in the form of a rigid foam, by hardening solutions of condensed tannins in the presence of oil and/or air or in the presence of a non-water-miscible volatile solvent and/or air. Also disclosed is the use of these materials in the areas of catalysis, chromatography, heat and sound insulation, tissue engineering and medication release and as a floral foam.
Porous silicon dioxide-carbon composite and method for preparing high-purity granular beta-phase silicon carbide powder with using the same
The present disclosure relates to porous silicon dioxide-carbon composites and a method for preparing high-purity -phase silicon carbide granular powders using the same. More particularly, it relates to a method for preparing high-purity -phase silicon carbide granular powders in accordance with a first step of preparing gel wherein carbon compounds are uniformly dispersed in silicon dioxide network structures generated by a sol-gel process using a silicon compound and a carbon compound in a liquid state as raw materials, a second step of preparing porous silicon dioxide-carbon composites, in which the carbon compounds are solidified, dried and then thermally treated to have a high specific area, and a third step of conducting both of a direct reaction between carbon and metallic silicon and a carbothermal reduction between carbon and silicon dioxide through a two-step treatment process of the prepared porous silicon dioxide-carbon composites powders with the added metallic silicon, wherein the average particle size, particle size distribution and purity of the silicon carbide powder can be adjusted by controlling a heating rate, a heat treatment temperature and time during the heat treatment process.
Metal-Nanostructure Composites
A metal-nanostructure composite includes a nanostructure-metal matrix composite. The nanostructure-metal matrix composite includes a host metal and nanofiller dispersed in the grains of the metal. The nanofillers can include both one-dimensional nanostructures (e.g., nano-tubes, nano-rods, nano-pillars, etc.) and two-dimensional nanostructures (e.g., graphene, nano-foam, nano-mesh, etc.) to improve the radiation resistance and mechanical properties of the host metal. A method of manufacturing the metal-nanostructure composite includes obtaining carbon nanotubes (CNTs) and encapsulating the CNTs with metal particles. The method also includes consolidating the encapsulated CNTs and forming (e.g., via extrusion) the consolidated metal/CNTs to produce the metal-nanostructure composite.
COATING SOURCE FOR PRODUCING DOPED CARBON LAYERS
A coating source for physical vapor deposition to produce doped carbon layers. The coating source is produced by way of sintering from pulverulent components and is formed of carbon as matrix material in a proportion of at least 75 mol % and at least one dopant in a proportion in the range from 1 mol % to 25 mol %.
Method of obtaining a silicon carbide-graphene composite with a controlled surface morphology
A method of obtaining a SiC-graphene composite with a controlled surface morphology having a surface covered with terraces or a network of pits where the method comprises providing a SiC substrate, annealing in an external beam of silicon atoms, and then cooling in an external beam of silicon atoms is disclosed.
NEGATIVE ELECTRODE ACTIVE MATERIAL, METHOD FOR PREPARING SAME, AND LITHIUM SECONDARY BATTERY COMPRISING SAME
The present invention relates to a negative electrode active material including metal-containing particles, wherein at least one of the angles, each angle formed between a straight line connecting the center point of the negative electrode active material and the center point of each of the metal-containing particles and the long axis of a corresponding one of the metal-containing particles, is in a range of 60 to 90. The present invention also relates to a method of manufacturing the negative electrode active material and to a lithium secondary battery including the negative electrode active material.
NEGATIVE ELECTRODE ACTIVE MATERIAL, METHOD FOR PREPARING SAME, AND LITHIUM SECONDARY BATTERY COMPRISING SAME
The present invention relates to a negative electrode active material including metal-containing particles, wherein at least one of the angles, each angle formed between a straight line connecting the center point of the negative electrode active material and the center point of each of the metal-containing particles and the long axis of a corresponding one of the metal-containing particles, is in a range of 60 to 90. The present invention also relates to a method of manufacturing the negative electrode active material and to a lithium secondary battery including the negative electrode active material.