Abstract: Novel methods of decreasing the concentration of hydroxyl ions in an electrochemically generated alkaline peroxide aqueous solution consisting of partial neutralization of a stabilized solution of alkaline hydrogen peroxide, electrodialysis, and dialysis of an aqueous solution of alkaline hydrogen peroxide. The methods of the invention can be performed at ambient temperature and pressure.
Abstract: A process for precipitating and removing chromium compounds in which chromium is in the hexavalent state from aqueous liquids, particularly, alkaline earth metal or alkali metal chlorate-rich solutions containing chloride, chlorate, and bichromate ions produced by the electrolysis of brine. In the process, hydroxylamine, hydroxylamine sulfate, hydroxylamine formate or hydroxylamine hydrochloride is used as a reducing agent to react and co-precipitate at a neutral or acid pH with hexavalent chromium ions present in the aqueous liquid, the reaction and precipitation taking place, generally, at a pH of about 4.0 to about 6.5 and, a temperature of about 50.degree. C. to about 100.degree. C. Precipitated oxides and hydroxides of divalent and trivalent chromium can be removed, for instance, by filtration.
Abstract: Novel magnesium hydroxide having a fine, plate-like crystalline structure, a median particle size of up to about 1 micron and a particle size distribution in which about 90% of said magnesium hydroxide particles are less than about 3.5 microns is prepared by a flash precipitation process in which less than or greater than an equivalent amount of alkaline material is reacted with a magnesium salt in a concentrated aqueous mixture thereof. Ultrasonic mixing means is used to combine heated aqueous streams of an alkaline material and a magnesium containing solution followed by a post heat treatment. The magnesium hydroxide is especially useful in providing flame retardancy in admixture with thermoplastic resins.
Abstract: Balanced pH, thermo-irreversible gels are ideal vehicles for drug delivery to a body cavity of a mammal. The gels contain a mixture of a polyoxyalkylene block copolymer or polyether together with an ionic polysaccharide which is thermo-irreversibly gelled in the presence of a counter-ion.
Type:
Grant
Filed:
August 7, 1990
Date of Patent:
September 1, 1992
Assignee:
Mediventures Incorporated
Inventors:
Tacey X. Viegas, Lorraine E. Reeve, Raymond L. Henry
Abstract: A process and compositions for reducing post-surgical adhesion formation/reformation in mammals following surgical injury to the peritoneal or pleural cavity or organs situated therein. Both aqueous and non-aqueous compositions comprising a polyoxyalkylene block copolymer are applied to injured areas of the peritoneal or pleural cavity or organs situated therein subsequent to surgical injury.
Abstract: A process and compositons for reducing post-surgical adhesion formation/reformation in mammals following injury to organs situated in mammalian body spaces. Aqueous, thermally reversible gel compositions, preferably at mammalian body fluid pH, comprising a polyoxyalkylene polymer and an ionic polysaccharide are applied to injured areas of the organs situated in body cavities such as, the peritoneal, pelvic, or pleural cavity. The aqueous gels are rendered thermally irreversible upon contact with a counter-ion.
Abstract: Novel methods of decreasing the concentration of hydroxyl ions in an electrochemically generated alkaline peroxide aqueous solution consisting of partial neutralization of a stabilized solution of alkaline hydrogen peroxide, electrodialysis, and dialysis of an aqueous solution of alkaline hydrogen peroxide. The methods of the invention can be performed at ambient temperature and pressure.
Abstract: An electrochemical cell having improved current efficiency and a method for electrochemically reacting a liquid electrolyte with a gas in an electrochemical cell. The cell has at least two electrodes separated by a cell separator wherein at least one of said electrodes is a porous, self-draining, gas diffusion electrode. In one embodiment of the invention, an electrolyte is flowed through said cell separator into a porous, self-draining electrode and simultaneously the electrode is fed with a mixture of a reactive gas and water or an electrolyte. In another embodiment of the invention in which the cell separator is an ion exchange permselective membrane, a mixture of a reactive gas and an electrolyte are fed to the porous, self-draining electrode. Preferably said porous, self-draining electrode is a cathode.
Type:
Grant
Filed:
August 25, 1989
Date of Patent:
November 13, 1990
Assignee:
H-D Tech Incorporated
Inventors:
Derek J. Rogers, Robert D. Klassen, Allan James, Indresh Mathur, Edward B. Noonan
Abstract: A bipolar, filter press type cell is disclosed having a liquid permeable diaphragm which is particularly suited for the electrolysis of a brine solution to produce chlorine and caustic or the electrolysis of an aqueous alkali metal hydroxide to produce an aqueous alkaline hydrogen peroxide solution. The cell can include a multiplicity of cell units extending generally in a vertical as well as a horizontal direction. A porous, self-draining electrode assembly includes a current distributor in contact with a side of the electrode opposite the electrolyte active side of the electrode.
Type:
Grant
Filed:
June 4, 1986
Date of Patent:
May 22, 1990
Assignee:
H-D Tech Inc.
Inventors:
Indresh Mathur, Allan James, David Bissett
Abstract: A porous diaphragm is disclosed for use in an electrochemical cell having at least one electrode characterized as porous and self-draining. The diaphragm provides a way of obtaining uniformity of flow of an electrolyte through the diaphragm even when exposed to varying electrolyte head pressures. The porous diaphragm of the invention has a plurality of layers of a microporous polyolefin film or a composite comprising the microporous polyolefin film and a support fabric resistant to deterioration upon exposure to an aqueous solution of an ionizable compound.
Abstract: A process and compositions for reducing post-surgical adhesion formation/reformation in mammals following surgical injury to the peritoneal or pleural cavity or organs situated therein. Both aqueous and non-aqueous compositions comprising a polyoxyalkylene block copolymer are applied to injured areas of the peritoneal or pleural cavity or organs situated therein subsequent to surgical injury.
Abstract: Process for the preparation of asymmetrical alkaline earth metal organoborates and organoaluminates represented by the formula I: ##STR1## and asymmetrical alkaline earth metal organoarsenates and organophosphates represented by the formula II: ##STR2## wherein Z is selected from the group consisting of boron and aluminum; X is selected from the group consisting of phosphorus and arsenic; M is an alkaline earth metal; and in which R.sub.1 -R.sub.6 are independently selected from alkyl, aryl, alkaryl, aralkyl, alkenyl, cycloalkyl, and cyano with the proviso that R.sub.1 -R.sub.6 are not all the same.
Type:
Grant
Filed:
December 8, 1988
Date of Patent:
February 13, 1990
Assignee:
The Dow Chemical Company
Inventors:
Richard C. Winterton, Ronald J. Hoffman, Thomas D. Gregory
Abstract: Alkaline earth metal anode cells having an intercalation cathode, a nonaqueous liquid electrolyte comprising (a) an organic solvent, for instance, an ether, an ester, a sulfone, an organic sulfide, an organic sulfate, a tertiary amine, an organic nitrite, and an organic nitrate, and (b) at least one of an electrolytically active alkaline earth metal salt comprising an organometallic alkaline earth metal salt represented by the formula: ##STR1## wherein Z is selected from the group consisting of boron and aluminum; X is selected from the group consisting of phosphorus and arsenic; M is an alkaline earth metal; and in which R.sub.1 -R.sub.6 are radicals independently selected from the following groups: alkyl, aryl, alkaryl, aralkyl, alkenyl, cycloalkyl, allyl, heterocyclic alkyl, and cyano, with the proviso that R.sub.1 -R.sub.6 cannot be all alkyl or all aryl and triarylalkylborate or aluminate anions, and trialkylarylborate or aluminate anions are excluded and M represents an alkaline earth metal.
Type:
Grant
Filed:
December 1, 1986
Date of Patent:
January 16, 1990
Assignee:
The Dow Chemical Company
Inventors:
Ronald J. Hoffman, Richard C. Winterton, Thomas D. Gregory
Abstract: A porous diaphragm is disclosed for use in an electrochemical cell having at least one electrode characterized as porous and self-draining. The diaphragm provides a uniformity of flow of an electrolyte through the diaphragm even when exposed to varying electrolyte head pressures. The porous diaphragm of the invention has a plurality of layers of a microporous polyolefin film or a composite comprising the microporous polyolefin film and a support fabric resistant to deterioration upon exposure to an aqueous solution of an ionizable compound.
Abstract: Cell having a porous, self-draining, gas diffusion electrode contained within a frame and having on both sides of said electrode a liquid permeable microporous diaphragm. The electrode assembly contains an internally positioned current distributor. The cell has two oppositely charged electrodes separated by the electrode assembly which divides a single electrolyte compartment. In operation, electrolyte is flowed into the electrolyte compartment and spent electrolyte is removed. In one embodiment of the invention, the electrolyte is internally circulated by turbulent flow of electrolyte as the result of the upward movement of gas released at an electrode.
Type:
Grant
Filed:
July 20, 1988
Date of Patent:
October 10, 1989
Assignee:
H-D Tech Inc.
Inventors:
Dennis F. Dong, Edward B. Noonan, Derek J. Rogers, Arthur L. Clifford, Katharina Benesch, Richard E. Loftfield
Abstract: An electrochemical cell and process for the electrolysis of an aqueous solution of an alkali metal halide and the production of a halogenated hydrocarbon comprising an electrolytic cell having a gas depolarized anode and a cathode which can be a dimensionally stable or a gas depolarized cathode wherein the production of an aqueous solution of an alkali metal hydroxide and a halogenated hydrocarbon are accompanied by significantly reduced voltage requirements in the cell.
Abstract: Electrochemical regeneration in an electrochemical cell of spent scrubbing solutions containing polvalent metal chelates is accomplished without substantial degradation of the chelate by controlling the anolyte pH and maintaining the anode potential of the cell above the oxidation potential of the polyvalent metal chelate but below the oxidation potential of the chelate portion of the polyvalent metal chelate.