Showing papers on "Ammonium hydroxide published in 2010"

Palladium/zirconium oxide nanocomposite as a highly recyclable catalyst for C-C coupling reactions in water.

Abstract: Palladium nanoparticles have been electrochemically supported on zirconium oxide nanostructured powders and all the nanomaterials have been characterized by several analytical techniques. The Pd/ZrO2 nanocatalyst is demonstrated to be a very efficient catalyst in Heck, Ullmann, and Suzuki reactions of aryl halides in water. The catalyst efficiency is attributed to the stabilization of Pd nanophases provided by tetra(alkyl)- ammonium hydroxide, which behaves both as base and PTC (phase transfer catalyst) agent.

Dilute Ammonia Pretreatment of Sorghum and Its Effectiveness on Enzyme Hydrolysis and Ethanol Fermentation

Abstract: A new pretreatment technology using dilute ammonium hydroxide was evaluated for ethanol production on sorghum. Sorghum fibers, ammonia, and water at a ratio of 1:0.14:8 were heated to 160 °C and held for 1 h under 140–160 psi pressure. Approximately, 44% lignin and 35% hemicellulose were removed during the process. Hydrolysis of untreated and dilute ammonia pretreated fibers was carried out at 10% dry solids at an enzyme concentration of 60 FPU Spezyme CP and 64 CBU Novozyme 188/g glucan. Cellulose digestibility was higher (84%) for ammonia pretreated sorghum as compared to untreated sorghum (38%). Fermentations with Saccharomyces cerevisiae D5A resulted in 24 g ethanol /100 g dry biomass for dilute ammonia pretreated sorghum and 9 g ethanol /100 g dry biomass for untreated sorghum.

Compositional Changes in Sugarcane Bagasse on Low Temperature, Long-term Diluted Ammonia Treatment

Abstract: Sugarcane bagasse is the major by-product of the sugar industry. It has a great potential for the production of biofuels and chemicals due to its considerable amount of cellulose and hemicellulose. In this study, we investigated a simple and economic pretreatment process using dilute ammonia for the storage of sugarcane bagasse. Sugarcane bagasse was stored in 0, 0.03, and 0.3% (w/w) ammonium hydroxide in a closed bottle for 40 days at 30 °C under atmospheric pressure without any agitation or circulation. Samples were taken every 10 days and analyzed for changes on lignin, cellulose, hemicellulose composition, ammonia concentration, and microbial counts. Biomass storage for 40 days at 0.3% ammonium hydroxide removed 46% of lignin and retained 100% cellulose and 73% hemicellulose.

Preparation of organic/inorganic hybrid silica using methyltriethoxysilane and tetraethoxysilane as co-precursors

Abstract: The preparation of a clear, organic/inorganic hybrid silica sol using methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) as co-precursors under alkaline conditions is reported. Two types of alkaline catalysts—ammonia and tetra-methyl-ammonium hydroxide (TMAH)—were examined for use in the preparation of colloidal sols of <100 nm in diameter, which are suitable for fabrication of nanoporous hydrophobic membranes. Factors that might influence sol preparation were investigated. When ammonia was used as the catalyst, the hydrolysis-polymerization reaction ratio decreased with both an increase in the molar ratio of MTES/TEOS, and a reduction in the water molar ratio. However, when TMAH was used as the catalyst, the water molar ratio had no effect on the hybrid sol preparation reactions. Even systems that employed higher molar ratios of MTES/TEOS or a lower water molar ratio relative to those of the original reactants, allowed for successful preparation of clear sols with a mean sol particle size of <40 nm.

Resist stripping compositions and methods for manufacturing electrical devices

Abstract: A liquid composition comprising (A) at least one polar organic solvent, selected from the group consisting of solvents exhibiting in the presence of from 0.06 to 4% by weight of dissolved tetramethylammonium hydroxide (B), the weight percentage being based on the complete weight of the respective test solution (AB), a constant removal rate at 50° C. for a 30 nm thick polymeric barrier anti-reflective layer containing deep UV absorbing chromophoric groups, (B) at least one quaternary ammonium hydroxide, and (C) at least one aromatic amine containing at least one primary amino group, a method for its preparation and a method for manufacturing electrical devices, employing the liquid composition as a resist stripping composition and its use for removing negative-tone and positive-tone photoresists and post etch residues in the manufacture of 3D Stacked Integrated Circuits and 3D Wafer Level Packagings by way of patterning Through Silicon Vias and/or by plating and bumping.

Extraction of solubles and microbial growth stimulants from lignocellulosic biomass and methods related thereto

Abstract: A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

Cleaning liquid used in photolithography and a method for treating substrate therewith

Abstract: It is disclosed a cleaning liquid for stripping and dissolving a photoresist pattern having a film thickness of 10-150 μm, which contains (a) 0.5-15 mass % of a quaternary ammonium hydroxide, such as tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, (b) 65-97 mass % of a water-soluble organic solvent, such as dimethylsulfoxide or a mixed solvent thereof with N-methyl-2-pyrrolidone, sulforane, etc., and (c) 0.5-30 mass % of water, and a method for treating a substrate therewith.

Cleaning agent for semiconductor provided with tungsten wiring

Abstract: PROBLEM TO BE SOLVED: To provide a cleaning agent for a semiconductor provided with tungsten and tungsten alloy wiring which is excellent in removal of an abrasive particle residue derived from an abrasive and removal of a metal residue on an insulating film and also excellent in tungsten corrosion inhibition in tungsten wiring. SOLUTION: The cleaning agent for a semiconductor provided with tungsten and tungsten alloy wiring contains organic amine (A), quaternary ammonium hydroxide (B), a chelating agent (C), and water (W) as essential ingredients, and its pH is 7.0-14.0. COPYRIGHT: (C)2011,JPO&INPIT

Linde Type-A zeolite synthesis and effect of crystallization on its surface acidity

Abstract: An alumino-silicate zeolite, Linde Type-A (LTA) has been prepared from aluminium powder and sodium metasilicate by hydrothermal process. The zeolite was characterized by FTIR and X-ray diffraction (XRD) analysis and by measuring the surface acidity using KOH as adsorbate. The surface acidity of LTA zeolite varied greatly with varying synthesized conditions such as crystallization temperature, crystallization time and K + ion adsorption period. The Bronsted acid site on the zeolite surface increased with increasing crystallization temperature and the maximum surface acidity was obtained at 100°C. Crystal growth was also dependent on the crystallization time. The surface acidity increased with increasing crystallization time. The maximum surface acidity due to the maximum consumption of the K + ion was observed at 48 h adsorption time and the value was found to be 0.9 meq/g when Si:Al was 50:50. It was seen that the surface acidity was more pronounced when ammonium hydroxide solution as adsorbate and agitated crystallization condition were used. The surface acidity of the commercial LTA zeolite was compared with the surface acidity of the synthesized LTA zeolite. It was found that the surface acidity of synthesized LTA zeolite is slightly greater than commercial LTA zeolite.

Double quaternary ammonium base compound and preparation method as well as application thereof

Abstract: The invention describes a double quaternary ammonium base compound with a general expression I, wherein in the general expression, R1 and R2 are mutually independent alkyls of C1-C18; R3, R4, R5 and R6 are mutually independent alkyls of a linear chain or a branch chain of C1-C6; and R7 is an alkylene of C2-C6 or alkoxy-substituted alkylene of C2-C6. The preparation method of the double quaternary ammonium base compound comprises the following steps: firstly, synthesizing double quaternary ammonium salt, and then, substituting the quaternary ammonium salt by the precipitation method to obtain the double quaternary ammonium base. The double quaternary ammonium base of the invention has the characteristics of novel structure, convenient preparation, low cost, and the like. The compound can be used as a condensation catalyst for condensation and hydrogenation of nitrobenzene and aniline to synthesize an intermediate 4-aminodiphenylamine of a rubber antioxidant. Compared with the common single quaternary ammonium base tetramethyl ammonium hydroxide, the compound of the invention has the advantages of convenient sources of raw materials, low cost, simple and convenient preparation processes, good heat stability, and the like.

Formulations and Method for Post-CMP Cleaning

Abstract: The present invention is a method of cleaning to removal residue in semiconductor manufacturing processing, comprising contacting a surface to be cleaned with an aqueous formulation having a polymer selected from the group consisting of acrylamido-methyl-propane sulfonate) polymers, acrylic acid-2-acrylamido-2-methylpropane sulfonic acid copolymer and mixtures thereof and a quaternary ammonium hydroxide having greater than 4 carbon atoms or choline hydroxide with a non-acetylinic surfactant. The present invention is also a post-CMP cleaning formulation having the components set forth in the method above.

Method of etching lanthanum-containing oxide layers

Abstract: Lanthanum oxide or lanthanoid-containing oxides are etched from substrates intended for microelectronic devices using a buffered halide solution, the active ingredient preferably comprising, consisting or consisting essentially of a salt of the formula: [NR 1 R 2 R 3 R 4 ] + X - wherein X = F, Cl, Br or I, and R 1 , R 2 , R 3 and R 4 may be the same or different from one another, and are selected from hydrogen, straight-chained C 1 -C 6 alkyls, branched C 1 -C 6 alkyls, substituted C 6 -C 14 aryl, unsubstituted C 6 -C 14 aryl, and combinations thereof. A fluoride-free active ingredient, e.g. ammonium chloride, is preferred. The pH is preferably in the range 3 to 6, and may be adjusted with a quaternary ammonium hydroxide such as tetramethylammonium hydroxide (TMAH). Contact times from about 5 seconds to about 10 minutes, at temperatures from about 5°C to about 60°C, are preferred. A passivating agent such as sorbitol, ethylene glycol, propylene glycol, glycerol or PEG may be used to reduce the etching rate.

Aqueous alkaline cleaning compositions and methods of their use

Abstract: The aqueous alkaline cleaning composition comprising (A) at least one thioamino acid having at least one secondary or tertiary amino group and at least one mercapto group and (B) at least one quaternary ammonium hydroxide; the use of the alkaline cleaning composition for the processing of substrates useful for fabricating electrical and optical devices; and a method for processing substrates useful for fabricating electrical and optical devices making use of the said aqueous alkaline cleaning composition.

Separation and Recovery of Tetramethyl Ammonium Hydroxide with Zeolitic Adsorbents

Abstract: Separation and recovery of tetramethyl ammonium hydroxide (TMAH) has been investigated, employing several zeolites as adsorbents. Zeolite X, prepared by using TMAH as a structure directing agent, possesses highest adsorption ability among the adsorbents investigated in the present work, which corresponds to the specific surface area and pore volume of the zeolite. The adsorption amount of TMAH with the zeolitic adsorbents increases with increase in pH value in the aqueous solution, indicating the adsorption progresses via cation exchange mechanism. The chromatographic operation is finally conducted, using granulated zeolitic adsorbents to prevent from the pressure-drop, and the quantitative adsorption-elution processing of TMAH can be achieved.

On Chemical Reactions and Staining Mechanisms

Abstract: Both terms relate to the formation of colloidal metallic silver (Latin argentum, Greek argyros) (1), which may be range in color from yellow through brown to black depending on particle size and density, in specific structural components of tissues. The metal is formed at sites of reduction of silver ions derived from a staining solution. These ions may be simple Ag+, as in a solution of silver nitrate, or they may be complex ions such as silver diammine, [Ag(NH3)2]+ or silver methenamine, [Ag3(C6H12N4)2]3+, which are formed respectively by adding ammonium hydroxide or hexamethylenetetramine to solutions of silver nitrate. (Hexamethylenetetramine, the reaction product of formaldehyde and ammonia, is also used as a urinary antiseptic; its pharmaceutical name in methenamine in the USA and hexamine in the UK.) These complex silver ions are more easily reduced than Ag+. By convention, argentaffin is used when the reducing agent is present in the tissue. Structures are said to be argyrophilic when bright light or a solution of a reducing agent is applied to the object after exposure to a silver solution.

Novel nanoscale solution method for synthesizing lithium cathode active materials

Abstract: The present invention relates to a solution based method for preparing an nano scale electroactive metal polyanion or a mixed metal polyanion comprising reacting metal sulfate—M(SO 4 ) x and/or other soluble metal salts, here M could be iron, cobalt, manganese, nickel or mixtures thereof, with a solution of sodium hydroxide with addition of solution of ammonium hydroxide, in the presence of water, drying the nano-intermediate M(OH) 2 or M 1 M 2 (OH) 2 or M 1 M 2 M 3 (OH) 2 , or MO(OH) or M 1 M 2 O(OH) or M 1 M 2 M 3 O(OH), mixing the dried intermediate with a soluble lithium precursor and soluble PO 4 containing precursor and a soluble polymer carbon, well mixed the mixture, and then removing said solvent at a temperature and for a time sufficient to remove the solvent and form an essentially dried mixture; and heating said mixture at a temperature and for a time sufficient to produce an electroactive metal polyanion or electroactive mixed metal polyanion. It is another object of the invention to provide electrochemically active materials produced by said methods. The electrochemically active materials so produced are useful in making electrodes and batteries.

Microwave-assisted fractional precipitation of magnetite nanoparticles using designed experiments

Abstract: In this study, highly pure magnetite nanoparticle dispersed in water and an organic solvent (n-hexane) and its powder form were prepared in laboratory scale by the fractional precipitation using ammonium hydroxide and microwave heating in the presence of linoleic acid as capping agent. In order to overcome the oxidation of Fe2+ during magnetite formation ferrous ammonium sulfate, sodium azide, and fractional precipitation technique were used. The Fe3O4 products were investigated by XRD, LLS, EDX, TEM, viscosity measurements, and chemical analysis. The effects of seven main factors on the average diameter of magnetite particles were studied by a screening design. The analysis of the samples showed that this new modified method is able to produce pure magnetite particles in the range of 1–15 nm. The most important factors on the particle size reduction of magnetite were found to be the capping agent used and the pH of solution at the end of precipitation process. Data analysis was performed using Qualitek-4 and Minitab softwares.

Electrochemical characterization of Cu dissolution and chemical mechanical polishing in ammonium hydroxide–hydrogen peroxide based slurries

Abstract: Chemical mechanical polishing (CMP) of copper in ammonium hydroxide based slurry in the presence of hydrogen peroxide was investigated. The polishing trend was found to be similar to that exhibited by other slurries containing hydrogen peroxide and various complexing agents used for Cu CMP. When the hydrogen peroxide concentration is increased, the polish rate increases, reaches a maximum and then decreases. The location and the magnitude of the maximum depend on the ammonium hydroxide concentration. The dissolution of copper in the NH4OH–hydrogen peroxide solution was probed by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) experiments. Electrical equivalent circuit (EEC) and reaction mechanism analysis (RMA) were employed to determine the mechanistic reaction pathway of Cu dissolution in NH4OH–hydrogen peroxide system. Based on the RMA analysis, a four step catalytic mechanism with two adsorbed intermediate species is proposed.