Abstract: A process is disclosed for the preparation of metallic products from metal salts admixed with solvent wherein at least one of the metal salt and the solvent is easily reducible. The admixture is heated under hypercritical conditions of temperature and pressure to produce metallic products and a hypercritical fluid. The hypercritical fluid is subsequently removed from the reaction zone and the metallic product is collected. The metallic product includes pure metals selected from the group of silver, gold, platinum, palladium, ruthenium, rhodium, mercury, arsenic, rhenium, tellurium, iridium, osmium, and copper, and alloys and mixtures thereof. The metallic product ordinarily exists as finely divided powders which may be highly porous.

Abstract: The present invention provides an improved, complex composite article of manufacture which comprises a network of high strength fibers having a tensile modulus of at least about 160 grams/denier and a tenacity of at least about 7 g/denier. An elastomeric matrix material substantially coats each of the individual fibers, and has a tensile modulus of less than about 6,000 psi, measured at 25.degree. C. The fibers in the matrix are provided with at least one additional rigid layer on a major surface of the fibers in the matrix to produce a rigid complex composite. Composites of this construction have improved resistance to environmental hazards, improved impact resistance, and are unexpectedly effective as ballistic resistant articles such as armor or helmets.

Abstract: A basified aqueous salt solution and an aqueous acid are generated in a multichamber two-compartment electrodialytic water splitter having unit cells comprised of a bipolar membrane, a first anion permselective membrane and at least one additional substantially non-porous, water-swollen non-cation permselective membrane disposed between an anion face of the bipolar membrane and a face of said first anion membrane thereby forming at least two base compartments and an acid compartment, positioned between an anode and a cathode.

Abstract: The present invention provides an improved electrodialytic water splitting process that may be operated in two- or three-compartment cells to recover valuable metal or ammonium values from materials comprising a salt of a first acid while avoiding formation of gas bubbles in the two- or three-compartment electrodialytic water splitting cells. The process comprises contacting a material comprising a salt of a first acid e.g. Na.sub.2 SO.sub.3, Na.sub.2 CO.sub.3 /NaHCO.sub.3, wherein the first acid is capable of generating a gas upon acidification of the salt of the first acid with a hydrogen ion-enriched aqueous solution comprising a second acid, e.g. Na.sub.2 SO.sub.4 /H.sub.2 SO.sub.4 which is generated and withdrawn from a two- or three-compartment electrodialytic water splitter. The gas generated e.g. CO.sub.2, SO.sub.2 is released external to the water splitter where it can be easily removed by conventional techniques such as application of vacuum.

Abstract: A process and a system for converting materials comprising sodium carbonate and sodium bicarbonate, such as dry-mined or subterranean deposits of trona, into a liquid comprising sodium carbonate substantially free of sodium bicarbonate. The process and the system incorporate the features of: (a) forming an aqueous solution comprising sodium carbonate and sodium bicarbonate; (b) removing a portion of said sodium bicarbonate from said solution to form a mother liquor comprising sodium carbonate and a reduced amount of sodium bicarbonate; (c) subjecting the mother liquor to electrodialytic water splitting by circulating the water liquor through an electrodialytic water splitter to produce a liquid reaction product comprising sodium carbonate substantially free of sodium bicarbonate; and (d) withdrawing the liquid reaction product comprising sodium carbonate substantially free of sodium bicarbonate from the electordialytic water splitter.

Abstract: Fibers prepared by spinning, drawing and drying dilute solutions of ultrahigh molecular weight polyethylene or polypropylene are modified by including in the dilute solution a polymeric additive. The polyethylene fibers so prepared have melting points above 140.degree. C. and exhibit improved adherence to matrices, resistance to fibrillation and other advantageous properties. Additives include lower molecular weight polyolefins, oxidized polyolefins, olefin copolymers, polyolefin graft copolymers and polyoxymethylenes.

Abstract: Conductive titanium silicide-containing films and composites comprising substrates and the film are produced by light induced chemical vapor deposition. The process eliminates the need to anneal the silicide film in order to produce a conductive film and overcomes the problem of substrate damage associated with high temperature deposition processes. The process comprises the steps of: exposing gas phase reactants comprising a titanium halide and a silicon containing compound to high intensity light; exposing a preheated substrate to the exposed gases to cause a conductive titanium silicide film to be formed thereon; and, maintaining the substrate, throughout the process, at a temperature below that temperature which would induce a thermal reaction between the gas phase reactants. The films and composites produced by the process are particularly suited for use in VLSI and VVLSI production.

Abstract: High tenacity, high modulus ultrahigh molecular weight fibers of polyethylene or polypropylene are coated with polyethylene, polypropylene or an ethylene and/or propylene copolymer. The coating improves certain properties of the monofilament or multifilament, including adhesion to various matrices in complex composites and resistance of the fiber to fibrillation.

Abstract: A molten polymer containing a blowing agent and, usually, a nucleating agent, is spun into fibers with screen packs or equivalent structures upstream of the spinning apertures. The use of screen packs enables the production of fibers with finer bubbles, which are therefore susceptable to greater melt-drawdown and postdrawing and can have better tensile properties. Foamed polyamide fibers are produced with average bubble diameters one-twentieth or less, compared to the effective fiber diameter.

Abstract: A method of producing ultrafine powders comprising metal silicide powder and the products produced by the method are disclosed. The ultrafine powders comprising metal silicide powders are ideally suited to form stable colloidal suspensions which are used in the production of conductive metal silicide containing films. The process employs gaseous reactants comprising a metal halide and a silicon-containing compound. The reactants are exposed to high intensity light to produce ultrafine powders. In addition to the production of metal silicide powders, the ultrafine powders may also include silicon powder and metal subhalide powder. The ultrafine powders are particularly suited for use in VLSI and VVLSI production.

Abstract: Finely divided, hydrogen-activated catalyst compositions comprising iron, silicon and carbon or iron and silicon that selectively convert gaseous mixtures of CO and H.sub.2, at a temperature of about 150.degree.-450.degree. C. and at pressures of about 10-2000 kPa, into a reaction mixture containing at least about 75% C.sub.2 -C.sub.6 alkenes and no more than about 25% of CH.sub.4 and undesirable CO.sub.2 by-products are disclosed. A wide range of iron/silicon-based catalyst compositions are conveniently prepared by laser pyrolysis and hydrogen-pretreatment and readily reactivated with hydrogen at elevated temperatures.

Abstract: Methods for removal of sulfur oxides, e.g., SO.sub.2 and SO.sub.3, from sulfuric acid tail gases by alkaline solution scrubbing, acidification of the alkaline scrubbing solution containing absorbed sulfur valves, liberation of concentrated SO.sub.2 from the acidified solution and regeneration of the alkaline scrubbing solution by means of two- or three-compartment electrodialytic water splitters are disclosed. A completely closed loop method suitable for continuous removal of sulfur oxides from sulfuric acid tail gas, recovery of concentrated SO.sub.2 for use in sulfuric acid plants, regeneration of alkaline scrubbing process solution and improvement in the water balance in sulfuric acid plant by use of two- and three-compartment electrodialytic water splitters is also disclosed.

Abstract: Solutions of ultrahigh molecular weight polymers such as polyethylene in a relatively non-volatile solvent are extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length. The first gels are extracted with a volatile solvent to form a second gel and the second gel is dried to form a low porosity xerogel. The first gel, second gel or xerogel, or a combination, are stretched. Among the products obtainable are polyethylene fibers of greater than 30 or even 40 g/denier tenacity and of modulus greater than 1000 or even 1600 or 2000 g/denier.

Abstract: A new polymerization catalyst system comprising an aluminum compound and a transition metal compound on an alumina-based aerogel support, a process for preparing the polymerization catalyst system and use of the catalyst system for polymerization and copolymerization of alpha-olefins are disclosed. A heat-activated alumina-based aerogel useful as a catalyst support and having a morphology by transmission electron microcopy comprising extremely thin folded film-like ribbons or plates and having a high BET surface area, high pore volume, and low bulk density is also disclosed.

Abstract: A molten polymer containing a blowing agent and, usually, a nucleating agent, is spun into fibers with screen packs or equivalent structures upstream of the spinning apertures. The use of screen packs enables the production of fibers with finer bubbles, which are therefore susceptable to greater melt-drawdown and post-drawing and can have better tensile properties. Foamed polyamide fibers are produced with average bubble diameters one-twentieth or less, compared to the effective fiber diameter.

Abstract: High tenacity, high modulus ultrahigh molecular weight fibers of polyethylene or polypropylene are coated with polyethylene, polypropylene or an ethylene and/or propylene copolymer. The coating improves certain properties of the monofilament or multifilament, including adhesion to various matrices in complex composites and resistance of the fiber to fibrillation.

Abstract: An apparatus is disclosed for generating an acidified aqueous salt solution and an aqueous base in a multichamber two-compartment electrodialytic water splitter which comprises alternating bipolar and first cation permselective membranes and at least one additional substantially non-porous, water-swollen cation permselective or neutral membrane disposed between a cation face of the bipolar membrane and a face of said first cation membrane thereby defining at least two acid compartments and a base compartment positioned between an anode and a cathode.

Abstract: Solutions of ultrahigh molecular weight polymers such as polyethylene in a relatively nonvolatile solvent are extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length. The first gels are extracted with a volatile solvent to form a second gel and the second gel is dried to form a low porosity xerogel. The first gel, second gel or xerogel, or a combination, are stretched. Among the products obtainable are polyethylene fibers of greater than 30 or even 40 g/denier tenacity and of modulus greater than 1000 or even 1600 or 2000 g/denier.

Abstract: A process and apparatus for converting alkali metal sulfate values, such as sodium or potassium sulfate values in spent rayon spin bath liquors, into alkali metal hydroxide and alkali metal sulfate/sulfuric acid by using two- or three-compartment electrodialytic water splitter cells. The process and apparatus incorporate the features of: (a) feeding a liquid comprising water to the base compartment of an electrodialytic water splitter, (b) feeding a liquid comprising alkali metal sulfate values to the remaining compartments of the electrodialytic water splitter (c) passing current through said electrodialytic water splitter to produce liquid comprising alkali metal sulfate and sulfuric acid in one of the remaining compartments and a liquid comprising alkali metal hydroxide in said base compartment. The liquid fed to the acid compartments of two- and three-compartment cells may contain H.sub.2 SO.sub.4. When more than about 5 weight percent H.sub.2 SO.sub.

Abstract: Semiconductor doping compositions comprising a suspension of (a) a dopant material, in the form of finely divided spherical particles of narrow size distribution from about 0.1 D to D, where D is the diameter of the largest particle and is no more than about (1.mu.) comprising a member selected from the group consisting of B.sub.x Si.sub.y, B.sub.x N.sub.y, P.sub.x Si.sub.y, P.sub.x N.sub.y, As.sub.x Si.sub.y and Sb.sub.x Si.sub.y wherein x and y vary from about 0.001 to about 99.999 mole percent, (b) an effective amount of a thermally degradable polymeric organic binder such as polymethyl methacrylate; and (c) an amount of an organic solvent, such a cyclohexanone, sufficient to dissolve said polymeric organic binder, such as polymethylmethacrylate, and to disperse said dopant material are disclosed.