摘要:
Described is a porous flexible sheet of about 93 to 99.5 weight percent amorphous precipitated silica and from about 0.5 to about 7 weight percent fibrillated, unsintered polymeric material, e.g., polytetrafluoroethylene. The sheet is useful as a separator in absorbed electrolyte gas recombinant batteries, e.g., lead-acid batteries, and has a tensile strength of less than 75 pounds per square inch (0.5 MPa). The sheet preferably has a porosity of from 85 to 92 percent and exhibits an electrical resistance of less than 3.5 milliohm-in.sup.2 /10 mil when saturated with 37 percent sulfuric acid. The sheet is prepared by subjecting a dry homogeneous mixture of the silica and polymeric material, e.g., polytetrafluoroethylene, in the above proportions to mechanical shear blending forces to fibrillate the polymer and thereafter dry forming the resulting admixture into sheet form.
摘要:
Corrosion inhibiting calcium-containing amorphous precipitated silica is described. The silica is prepared by admixing simultaneously in a reactor aqueous alkali metal silicate, e.g., sodium silicate, acidifying agent, e.g., hydrochloric acid, and a water-soluble source of calcium, e.g., calcium chloride. The product contains from 6 to 9 weight percent calcium (as CaO). The silica product may be incorporated into a coating composition used for corrodible metallic surfaces.
摘要:
Disclosed is a method of electrolyzing alkali metal chloride brine between an anode and a cathode, with oxidant feed to the cathode, where the cathode is a bed of porous particles having HO.sub.2.sup.- disproportionation catalyst. Also disclosed is an electrolytic cell for carrying out the disclosed process.
摘要:
Disclosed is a solid polymer electrolyte electrolytic cell where one member of the anode cathode electrode pair forms a solid polymer electrolyte with a permionic membrane, and the opposite member is spaced from the permionic membrane.
摘要:
Disclosed is a method of reducing the cathodic voltage of an electrolytic cell while electrolytically producing alcohols, aldehydes, acids, and ketones from peroxy bond-containing organic compounds such as peracids, peroxides, hydroperoxides, and derivatives thereof. According to the disclosed method, the peroxy bond-containing organic compound is fed to the catholyte compartment of an electrolytic cell and an aqueous chloride solution, e.g., sodium chloride or hydrochloric acid, is fed to the anolyte chamber of the cell while passing an electrical current from an anode of the cell to a cathode of the cell. Chlorine is recovered as the anodic product of the cell while the reaction products of the peroxy bond-containing organic compound are recovered as cathodic products. Also disclosed is a method of electrolyzing aqueous chloride solutions, e.g., sodium chloride solutions, and hydrochloric acid solutions at a reduced cell voltage. In addition to the steps of feeding the chloride solution to an electrolytic cell, passing an electrical current from an anode of the cell to the cathode of the cell, evolving chlorine on the anode of the cell, and recovering the chlorine gas from the anolyte chamber of the cell, the disclosed method also includes feeding an oxidant to the catholyte chamber of the cell and recovering cathodic reaction products of the oxidant, in addition to water and alkali metal hydroxides, from the catholyte chamber. Disclosed oxidants include organic compounds containing peroxy bonds such as peracids, peroxides, hydroperoxides, and their derivatives where the cathodic reaction products of the oxidant are alcohol, ketone, aldehyde, or acid corresponding to the peroxy-containing organic oxidant.
摘要:
Disclosed is an improved method of conducting electrolysis where a first electrode and a second electrode are inserted in an electrolyte, and an electrical current passes from one of the electrodes to the other electrode. At least one of the electrodes has an oxide coating formed in situ on an electroconductive substrate. According to the disclosed method, an external portion of the coating is abraded to expose an inner portion of the coating.
摘要:
An active agent delivery device comprises (a) microporous material comprising a matrix consisting essentially of linear ultrahigh molecular weight polyolefin, a large proportion of finely divided water-insoluble filler of which at least about 50 percent by weight is siliceous, and interconnecting pores; and (b) a releasable active agent or precursor thereof associated with at least a portion of the filler.
摘要:
Granular calcium hypochlorite containing from about 0.001 to about 1.0 weight percent of finely-divided polyfluorinated polymer, e.g., polytetrafluoroethylene, dispersed throughout the granules is described. The product may be compressed and formed into shaped articles, e.g., tablets. The granules may be prepared by admixing the polyfluorinated polymer with particulate calcium hypochlorite, compacting the mixture and granulating the compacted product. Tablets prepared from the polyfluorinated polymer containing granular calcium hypochlorite dissolve in water at a rate slower than tablets prepared without the polyfluorinated polymer. Finely-divided calcium hypochlorite powder, e.g., powder of less than about 10 microns in size, is rendered more conveyable and compactible by the addition of the finely-divided polyfluorinated polymer; and mixtures of finely-divided calcium hypochlorite powder and particulate calcium hypochlorite is rendered more readily compactible.
摘要:
Granular calcium hypochlorite containing from about 0.001 to about 1.0 weight percent of finely-divided polyfluorinated polymer, e.g., polytetrafluoroethylene, dispersed throughout the granules is described. The product may be compressed and formed into shaped articles, e.g., tablets. The granules may be prepared by admixing the polyfluorinated polymer with particulate calcium hypochlorite, compacting the mixture and granulating the compacted product. Tablets prepared from the polyfluorinated polymer containing granular clacium hypochlorite dissolve in water at a rate slower than tablets prepared without the polyfluorinated polymer. Finely-divided calcium hypochlorite powder, e.g., powder of less than about 10 microns in size, is rendered more conveyable and compactible by the addition of the finely-divided polyfluorinated polymer; and mixtures of finely-divided calcium hypochlorite powder and particulate calcium hypochlorite is rendered more readily compactible.
摘要:
Disclosed is a method of electrolyzing alkali metal chloride brine between an anode and a cathode, with oxidant feed to the cathode, where the cathode is a bed of porous particles having HO.sub.2.sup.31 disproportionation catalyst. Also disclosed is an electrolytic cell for carrying out the disclosed process.