摘要:
A process is provided for converting potassium chloride to potassium bicarbonate with desirable conversions which bicarbonate can then be calcined to potassium carbonate. In one embodiment the potassium bicarbonate is formed in a reaction medium which is an admixture of water and a water miscible alcohol with the other reactants employed being carbon dioxide and an alkylamine. In a more preferred embodiment an alcoholic solution of an alkylamine which solution is saturated with carbon dioxide will be prepared and then an aqueous solution of a potassium halide, preferably potassium chloride, will be added to the alcoholic solution so as to form potassium bicarbonate.
摘要:
A process is provided for producing carbon free borosilicate glass compositions by hydrolyzing a silicon tetraalkoxide so as to form an at least partially hydrolyzed silicon tetraalkoxide which is then combined with a boron alkoxide and sufficient water to produce a substantially hydrolyzed borosiloxane, or borosilicate precursor, and then this precursor in the presence of free water is fractionally distilled for a time sufficient to remove all alkanol by-product.
摘要:
A process is provided for producing carbon-free homogeneous silicate compositions comprising;Combining a hydrolyzable metal alkoxide with a clear solution of a partially hydrolyzed silicon tetraalkoxide so as to form a clear solution of a further hydrolyzable metallosiloxane;Adding an additional quantity of water to said solution in an amount in excess of that required to theoretically hydrolyze residual alkoxy groups of said further hydrolyzable metallosiloxane, thereby forming a substantially hydrolyzed metallosiloxane;Fractionally distilling said substantially hydrolyzed metallosiloxane, i.e. heating under a fractionating column, in the presence of free water for a time sufficient to remove all residual alcohol as distillate and hydrolyze residual alkoxy groups.
摘要:
Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (.about.1.10-1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm.
摘要:
A two-step method is described for making transparent aerogels which have a density of less than 0.003 g/cm.sup.3 to those with a density of more than 0.8 g/cm.sup.3, by a sol/gel process and supercritical extraction. Condensed metal oxide intermediate made with purified reagents can be diluted to produce stable aerogels with a density of less than 0.02 g/cm.sup.3. High temperature, direct supercritical extraction of the liquid phase of the gel produces hydrophobic aerogels which are stable at atmospheric moisture conditions. Monolithic, homogeneous silica aerogels with a density of less than 0.02 to higher than 0.8 g/cm.sup.3, with high thermal insulation capacity, improved mechanical strength and good optical transparency, are described.
摘要翻译:描述了通过溶胶/凝胶法和超临界萃取法制备密度小于0.003g / cm 3的透明气凝胶至密度大于0.8g / cm 3的透明气凝胶的两步法。 用纯化试剂制成的冷凝金属氧化物中间体可以稀释,以产生密度小于0.02g / cm3的稳定气凝胶。 高温,直接超临界萃取凝胶的液相产生在大气湿度条件下稳定的疏水性气凝胶。 描述了具有小于0.02至高于0.8g / cm 3的密度的均匀二氧化硅气凝胶,具有高绝热能力,改进的机械强度和良好的光学透明性。
摘要:
Aluminum phosphate is made in ultrapure form by reaction between phosphoric acid and an aluminum alkoxide. Cast articles may be made by using the liquid reaction intermediate product as a binder in sintering of particles of aluminum phospate.
摘要:
A method for forming optical parts used in laser optical systems such as high energy lasers, high average power lasers, semiconductor capital equipment and medical devices. The optical parts will not damage during the operation of high power lasers in the ultra-violet light range. A blank is first ground using a fixed abrasive grinding method to remove the subsurface damage formed during the fabrication of the blank. The next step grinds and polishes the edges and forms bevels to reduce the amount of fused-glass contaminants in the subsequent steps. A loose abrasive grind removes the subsurface damage formed during the fixed abrasive or "blanchard" removal process. After repolishing the bevels and performing an optional fluoride etch, the surface of the blank is polished using a zirconia slurry. Any subsurface damage formed during the loose abrasive grind will be removed during this zirconia polish. A post polish etch may be performed to remove any redeposited contaminants. Another method uses a ceria polishing step to remove the subsurface damage formed during the loose abrasive grind. However, any residual ceria may interfere with the optical properties of the finished part. Therefore, the ceria and other contaminants are removed by performing either a zirconia polish after the ceria polish or a post ceria polish etch.
摘要:
A process for forming a doped oxide film suitable for doping a semiconductor wafer substrate material and composite article. A silicon tetra-alkoxide is reacted with a limited amount of water to produce a low molecular weight, soluble polyorganosiloxane. The polyorganosiloxane is subsequently admixed with a reactive dopant source to form a soluble metallosiloxane polymer. The metallosiloxane polymer is coated onto a semiconductor wafer substrate material to produce a metallosiloxane-wafer composite article. The composite article is heated to produce an impurity doped semiconductor wafer suitable for electronic applications.
摘要:
Alkoxy ethoxides, for example 2-methoxy ethoxide, of aluminum and magnesium or aluminum and calcium, are provided. These compounds are of the formula MAl.sub.2 (O--CH.sub.2 --CH.sub.2 --O--R).sub.8 wherein M is calcium or magnesium and wherein R is an alkyl of 1 to 4 carbon atoms; they are liquids at about 25.degree. C. and about 1 atmosphere of pressure and are produced by reacting aluminum and magnesium or calcium with mono-alkyl ethers of ethylene glycol. Methods for hydrolyzing the compounds to obtain oxides of the formula MgAl.sub.2 O.sub.4 and CaAl.sub.2 O.sub.4 are disclosed. For example, magnesium aluminum octa-(2 methoxy ethoxide) is produced, using ethylene glycol monomethyl ether (methyl "Cellosolve") as a reagent; the material is hydrolyzed and heated to form MgAl.sub.2 O.sub.4.
摘要翻译:提供了铝和镁或铝和钙的烷氧基乙氧基化物,例如2-甲氧基乙氧基化物。 这些化合物具有式MA1(O-CH2-CH2-O-R)8,其中M是钙或镁,其中R是1至4个碳原子的烷基; 它们在约25℃和约1大气压下是液体,并且通过使铝和镁或钙与乙二醇的单烷基醚反应来制备。 公开了水解化合物以获得式MgAl 2 O 4和CaAl 2 O 4的氧化物的方法。 例如,使用乙二醇单甲醚(甲基“Cellosolve”)作为试剂制造八(2-甲氧基乙氧化镁)镁铝; 将材料水解并加热形成MgAl 2 O 4。
摘要:
A two-step hydrolysis-condensation method was developed to form metal oxide aerogels of any density, including densities of less than 0.003g/cm.sup.3 and greater than 0.27g/cm.sup.3. High purity metal alkoxide is reacted with water, alcohol solvent, and an additive to form a partially condensed metal intermediate. All solvent and reaction-generated alcohol is removed, and the intermediate is diluted with a nonalcoholic solvent. The intermediate can be stored for future use to make aerogels of any density. The aerogels are formed by reacting the intermediate with water, nonalcoholic solvent, and a catalyst, and extracting the nonalcoholic solvent directly. The resulting monolithic aerogels are hydrophobic and stable under atmospheric conditions, and exhibit good optical transparency, high clarity, and homogeneity. The aerogels have high thermal insulation capacity, high porosity, mechanical strength and stability, and require shorter gelation times than aerogels formed by conventional methods.