212 results about "Near critical" patented technology

Methods of oxidizing multiwalled carbon nanotubes are provided. The multiwalled carbon nanotubes are oxidized by contacting the carbon nanotubes with gas-phase oxidizing agents such as CO₂, O₂, steam, N₂O, NO, NO₂, O₃, and ClO₂. Near critical and supercritical water can also be used as oxidizing agents. The multiwalled carbon nanotubes oxidized according to methods of the invention can be used to prepare rigid porous structures which can be utilized to form electrodes for fabrication of improved electrochemical capacitors.

For small angles that are near critical angle, a primary incident X-ray beam has excellent depth resolution. A series of X-ray fluorescence measurements are performed at varying small angles and analyzed for depth profiling of elements within a substrate. One highly useful application of the X-ray fluorescence measurements is depth profiling of a dopant used in semiconductor manufacturing such as arsenic, phosphorus, and boron. In one example, angles are be varied from 0.01° to 0.20° and measurements made to profile arsenic distribution within a semiconductor wafer. In one embodiment, measurements are acquired using a total reflection X-ray fluorescence (TXRF) type system for both known and unknown profile distribution samples. The fluorescence measurements are denominated in counts/second terms and formed as ratios comparing the known and unknown sample results. The count ratios are compared to ratios of known to unknown samples that are acquired using a control analytical measurement technique. In one example the control technique is secondary ion mass spectroscopy (SIMS) so that the count ratios from the TXRF-type measurements are compared to ratios of integrals of SIMS profiles. In another example, the TXRF-type measurement ratios are compared to simulation profiles of known samples. Integrals of the SIMS profile that vary as a function of depth into the substrate correspond to the grazing incidence angles of the TXRF-like measurement and respective count rates.

The invention may be practiced to make graphite composites. Preferred composites which may be made in accordance with the invention include conductive polymeric composites (thermally or electrically), paint composites, battery composites, capacitor composites, and pollution abatement catalyst support composites. One method of making the graphite aforementioned composites includes introducing an intercalant into at least one interstice of at least one flake of natural graphite. The method also includes introducing a fluid into the at least one interstices of the flake. Preferably, the fluid comprises at least one of a sub-critical fluid, near critical point fluid, or a supercritical fluid. Furthermore the method includes blending the flake with a polymer, thereby forming a graphite-polymeric composite.

The invention relates to a process for producing furfural from xylose comprising: (a) mixing an aqueous xylose solution containing xylose oligosaccharides with sub-critical or near-critical water to form a mixture at a first temperature and a first pressure; (b) maintaining the mixture at the first temperature and the first pressure for a first time period; and (c) rapidly cooling the mixture to a second temperature and a second pressure, wherein furfural is produced by the process (d) process can also be carried out with or without mixing of carbon dioxide with aqueous xylose solution before it is mixed with sub-critical or near-critical water to form a mixture at a first temperature and pressure.

A partially hydrogenated fatty substance produced by partial hydrogenation of a substrate, such as vegetable, animal or marine oil, said partially hydrogenated substance having a low content of trans fatty acids. When the hydrogenation degree is below 30% the trans-fatty acid concentration can be expressed in the following way: trans<=0.3x(initial IV-IV) in %. of the total amount of fatty acids, wherein IV refers to iodine value. When the hydrogenation degree is between 30 and 70% the trans-fatty acid concentration can be expressed with: trans<=0.09xinitial IV in % of the total amount of fatty acids. The partial hydrogenation is performed by a process in which the substrate, hydrogen gas and a solvent are mixed, and the whole mixture is brought into a supercritical or near-critical state. This substantially homogeneous super-critical or near-critical solution is led over the catalyst, whereby the reaction products formed, i.e. the hydrogenated substrates, will also be a part of the substantially homogeneous super-critical or near-critical solution.

The invention provides a method for forming particles of a target substance (26), involving: (a) preparing a solution or suspension of the substance in a vehicle (21) which is or includes either a near-critical fluid (21) or a first supercritical fluid; (b) introducing the solution or suspension into a particle formation vessel (32); and (c) contacting the solution or suspension, in the particle formation vessel, with a second super-critical fluid, under conditions which allow the second supercritical fluid to cause precipitation of particles of the target substance from the solution or suspension; wherein the second supercritical fluid is miscible or substantially miscible with the vehicle and is a fluid in which the target substance is insoluble or substantially insoluble. Also provided is apparatus for use in carrying out an embodiment of the method, including a particle formation vessel and means for controlling the temperature and pressure inside it; a fluid mixing vessel and means for controlling the temperature and pressure inside it; first fluid inlet means for introducing into the fluid mixing vessel a vehicle and a solution of a target substance in a primary solvent, so as to form in the fluid mixing vessel a solution of the substance and the primary solvent in the vehicle; and second fluid inlet means for introducing the solution thus formed, preferably together with a second supercritical fluid, into the particle formation vessel. The invention also provides a particulate product formed using the method.

A flexible multi-tubular cryoprobe, including a housing for receiving an inlet flow of near critical cryogenic fluid from a fluid source and for discharging an outlet flow of the cryogenic fluid. A plurality of fluid transfer tubes are securely attached to the housing. This includes a set of inlet fluid transfer tubes for receiving the inlet flow from the housing; and, a set of outlet fluid transfer tubes for discharging the outlet flow to the housing. Each of the fluid transfer tubes is formed of material that maintains flexibility in a full range of temperatures from −200° C. to ambient temperature. Each fluid transfer tube has an inside diameter in a range of between about 0.10 mm and 1.0 mm and a wall thickness in a range of between about 0.01 mm and 0.30 mm. An end cap is positioned at the ends of the plurality of fluid transfer tubes to provide fluid transfer from the inlet fluid transfer tubes to the outlet fluid transfer tubes.

An expandable, flexible multi-tubular cryoprobe operational with a near critical cryogenic working fluid. The inlet fluid transfer micro-tubes utilized are formed of material that maintains flexibility in a full range of temperatures from −200° C. to ambient temperature. During operation, the cryoprobe is mechanically actuated to provide radial expansion of the inlet fluid transfer micro-tubes. Thus, enhanced thermal contact with target biological tissue to be treated is provided.

Methods are disclosed for depositing materials selectively and controllably from liquid, near-critical, and/or supercritical fluids to a substrate or surface controlling the location and/or thickness of material(s) deposited to the surface or substrate. In one exemplary process, metals are deposited selectively filling feature patterns (e.g., vias) of substrates. The process can be further used to control deposition of materials on sub-surfaces of composite or structured silicon wafers, e.g., for the deposition of barrier films on silicon wafer surfaces. Materials include, but are not limited to, overburden materials, metals, non-metals, layered materials, organics, polymers, and semiconductor materials. The instant invention finds application in such commercial processes as semiconductor chip manufacturing. In particular, selective deposition is envisioned to provide alternatives to, or decrease need for, such processes as Chemical Mechanical Planarization of silicon surfaces in semiconductor chip manufacturing due to selective filling and/or coating of pattern features with metals deposited from liquid, near-critical, or supercritical fluids.

A method of forming a layer of high-k dielectric material in an integrated circuit includes preparing a silicon substrate; forming a high-k dielectric layer by a sequence of ALD cycles including: depositing a first layer of metal ligand using ALD with an oxygen-containing first precursor; and depositing a second layer of metal ligand using ALD with a second precursor; repeating the sequence of ALD cycles N times until a near-critical thickness of metal oxide is formed; annealing the substrate and metal oxide layers every N ALD cycles in an elevated temperature anneal; repeating the sequence of ALD cycles and elevated temperature anneals until a high-k dielectric layer of desired thickness is formed; annealing the substrate and the metal oxide layers in a final annealing step; and completing the integrated circuit.

A near critical fluid based cryoablation system comprises a cryoablation catheter for creating a lesion in tissue. A cryogenic fluid is transported under pressure through the catheter. A controller adjusts the pressure from a relatively high (e.g., near critical) pressure to a substantially lower pressure based on a condition during the catheter activation. In one configuration, the pressure is modulated based on the temperature of the catheter. When the temperature of the catheter reaches a target temperature, the pressure is reduced.

Methods are disclosed for the continuous treatment of biomass comprising a pretreatment step, wherein said biomass is contacted with a first supercritical, near-critical, or sub-critical fluid to form a solid matrix and a first liquid fraction; and a hydrolysis step, wherein said solid matrix formed in said pretreatment step is contacted with a second supercritical or near-supercritical fluid to produce a second liquid fraction and a insoluble lignin-containing fraction. Also disclosed are apparatuses for the continuous conversion of biomass comprising a pretreatment reactor and a hydrolysis reactor associated with said pretreatment reactor.

Vessels and methods for esterification and transesterification of fatty acids under near critical or supercritical reaction conditions are disclosed herein. Alkyl esters produced in the vessel with the disclosed methods are used to create biofuel, such as biodiesel.

The invention belongs to the technical field of processing of high molecular material, and in particular relates to a method for preparing a crystalline polyether-ether-ketone foam material. By the method, the content of crystal in polyether-ether-ketone and the thickness and the perfection of a laminated crystal are controlled by controlling saturation temperature, saturation pressure and saturation time by using near-critical or supercritical carbon dioxide as a physical foaming agent so as to prepare the polyether-ether-ketone foam material with high performance. By the method, the defects that the gas saturation time is long, the solubility is small, the growth of a foam hole and morphology crystallized area are limited and the like are overcome, so that by controlling technological parameters, the high-performance foam material with the low-intensity and the high foaming ratio is effectively prepared, the application field of polyether-ether-ketone is widened, and the blank of a domestic high-performance crystalline polyether-ether-ketone foaming technology is made up.

A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.