Abstract:
Sensing elements, sensor systems and methods for determining the concentration of oxygen and oxygen-related analytes in a medium are provided. The sensing element comprises a solid polymeric matrix material that is permeable to oxygen or an oxygen related analyte and an indicator that is covalently bonded to the solid polymeric matrix material. The indicator is a luminescent platinum group metal polyaromatic chelate complex capable of having its luminescence quenched by the presence of oxygen. The polyaromatic complex comprises three ligands, at least one of which is a bidentate diphenylphenanthroline. The polyaromatic complex is distributed substantially homogenously throughout the matrix material and is covalently bonded to the matrix material via a linker arm. The linker arm is attached to a phenyl group of a diphenylphenanthroline ligand and to the backbone of the polymeric matrix material. The sensor systems comprise the present sensing element, an excitation assembly, a detector assembly, and a processor assembly.
Abstract:
A method and composition for the removal of contaminants in a gas stream used in the contamination sensitive processes of photolithography and metrology are described. The synergistic effect of a combination of an electropositive metal component, a high silica zeolite, and a late transition metal compound effects removal or reduction of the contaminates in the gas which interfere with light transmittance to the ppb or ppt levels necessary for the gas to be suitable for these uses. The removal of neutral polar molecules, neutral polar aprotic molecules, protic and aprotic alkaline molecules, acidic polar species, and neutral non-polar aprotic molecules is accomplished with the claimed composition. Depending on the type of contaminant, the composition components are each varied from 10 to 80 parts by volume, with the total composition limited to 100 parts by volume.
Abstract:
A method of purifying a hydrogen stream using an electrochemical cell having an enclosed electrically conductive cylindrical outer shell and a hollow wet polymeric membrane located within and parallel to the longitudinal axis of the cylindrical member which provides an inner compartment and an outer compartment. An electrode having a longitudinal axis is located within the inner compartment and is spaced from the hollow polymeric membrane. A gas inlet for feeding a hydrogen stream that is to be purified communicates with the inner compartment and a gas outlet is provided for passing purified hydrogen gas thru the cylindrical outer shell. The electrode within the hollow wet polymeric membrane is connected to an anode terminal of a dc supply with an electrical conductor and the outer shell of the cylindrical shaped member is connected to a cathode terminal of the dc supply with another electrical conductor.
Abstract:
A method and apparatus for the decontamination of fluid ammonia are described. Liquid or gaseous ammonia is purified of contaminants by passage through an adsorbent bed, the contaminants accumulating in the bed. A portion of the purified ammonia discharged from the bed is decomposed to hydrogen and nitrogen. The hydrogen is used to regenerate an adsorbent bed which has accumulated sufficient contaminants to reduce its ability to further decontaminate incoming ammonia satisfactorily. Preferably there are a plurality of interconnected adsorbent beds, with some being operated for ammonia decontamination while others are being regenerated, with their operations being reversed as needed to maintain a continual production of decontaminated ammonia from the plurality of beds. Computers or other controllers can be used to control such bed operations and interchanges. Internal production of hydrogen makes the system self-contained and no addition of hydrogen is needed.
Abstract:
A process and apparatus for the decontamination of gaseous contaminants (especially oxygen, carbon dioxide and water vapor) from hydride gases (including their lower alkyl analogs) down to ≦100 ppb contaminant concentration are described. The critical component is a high surface area metal oxide substrate with reduced metal active sites, which in various physical forms is capable of decontaminating such gases to ≦100 ppb, ≦50 ppb or ≦10 ppb level without being detrimentally affected by the hydride gases. The surface area of the substrate will be ≧100 m2/g, and preferably 200-800 m2/g. Oxides of various metals, especially manganese or molybdenum, can be used, and mixtures of integrated oxides, or one type of oxide coated on another, may be used. The substrate is preferably retained in a hydride-gas-resistant container which is installed in a gas supply line, such as to a gas- or vapor-deposition manufacturing unit. The invention provides final decontamination for hydride gas streams intended for gas- or vapor-deposition formation of high purity LED, laser (especially blue laser), electronic, optical or similar products, and can be used in combination with upstream preliminary decontamination process and/or upstream or downstream solid particulate removal units.
Abstract:
The present invention discloses a method for the removal of a number of molecular contaminants from surfaces within a device. A purge gas containing oxygen and/or water is introduced into the interior of the device, contacting at least a portion of the interior surfaces. A contaminated purge gas is produced by transferring a portion of the contamination from the interior surfaces into the purge gas. The contaminated purge gas is removed from the device and the process is continued until the contaminant concentration in the contaminated purge gas is below a predetermined level.
Abstract:
The invention is a method for the decontamination of CO2 to a sufficient level of purity to allow it to be used in the semiconductor industry. The invention comprises the exposure of fluid CO2 to a combination metallic states of at least one metal under the appropriate conditions for removal of contaminants. The adsorbents are then decontaminated/activated to return the adsorbent to a mixed oxidation state and allow further rounds of decontamination. The adsorbents are selected to be complimentary to each other, preferentially adsorbing different contaminants. Additionally, the adsorbents are selected to undergo reduction differently such that upon regeneration only a portion of the metals are reduced and the adsorbent is returned essentially to its original state.
Abstract:
A method is described for rapid and economical activation and/or preconditioning of gas purification substrates by providing forced convection of the preconditioning or activating gas through the pores of the substrate. The gas is pumped into the substrate-containing vessel and raised to an elevated pressure, which is maintained for a short predetermined time, followed by venting of contents of the vessel. The vessel is again pressurized with the purging gas to an elevated level, and the elevated pressure is maintained for a short predetermined time, followed by venting of the vessel. This cycle is repeated as often as needed or desired. Activation and/or preconditioning can be accomplished in a much shorter time and with much less gas usage compared to diffusion preconditioning and activation processes. This process is particularly suited for preconditioning and activation of gas purifier substrates for decontamination of gases down to ≦1 ppm contaminants.
Abstract:
A method for hydride gas purification uses materials having at least one lanthanide metal or lanthanide metal oxide. The method reduces contaminants to less than 100 parts per billion (ppb), preferably 10 ppb, more preferably 1 ppb. The material can also include transition metals and transition metal oxides, rare earth elements and other metal oxides. The invention also includes materials for use in the method of the invention.
Abstract:
The present invention discloses a method for the removal of a number of molecular contaminants from surfaces within a device. A purge gas containing oxygen and/or water is introduced into the interior of the device, contacting at least a portion of the interior surfaces. A contaminated purge gas is produced by transferring a portion of the contamination from the interior surfaces into the purge gas. The contaminated purge gas is removed from the device and the process is continued until the contaminant concentration in the contaminated purge gas is below a predetermined level.