Abstract: The present invention relates to a polymer-matrix material including a non-ionic solid matrix and a polymer, wherein the polymer is present on a surface of the non-ionic solid matrix and within an interior bulk of the non-ionic solid matrix. The present invention also relates to methods for forming a polymer within a non-ionic solid matrix. These methods include transporting a polymer precursor or a polymerizing reagent on and into the non-ionic solid matrix and exposing the non-ionic solid matrix to a polymerizing reagent or polymer precursor, respectively, under conditions effective to polymerize the polymer precursor within the non-ionic solid matrix.

Abstract: A method and apparatus for compensating for charging current at a working electrode of an electrochemical cell. And a method for measuring faradaic current at the working electrode. Includes measuring the current at the working electrode while a time-varying potential difference is applied between the working electrode and a reference electrode. And while the applied potential difference is held constant for a short time and the working electrode current is again measured, where this current is the faradaic current. The faradaic current is then filtered from the total current to determine the charging current thereby compensating for double layer charging current in the cell.

Abstract: A process for purifying water containing fluoride which comprises precipitating fluoride from the water as fluorapatite in the presence of a bed of seeding composition. Fluoride is removed as fluorapatite by having sufficient available calcium for each mole of fluoride present in the water and sufficient available phosphate for each mole of fluoride in the water to form a precipitate which is or converts to sufficient fluorapatite to remove essentially all fluoride from the water.

Abstract: The gas monitor of the present invention is capable of simultaneously determining the concentrations of two members of a family of oxygen-containing gases present in an air sample. The monitor utilizes a four electrode potentiostat (58, 70, 12, 14) including two indicating electrodes (58, 70) mounting in a single electrochemical cell (8) and immersed in an aqueous electrolyte (10). The air sample containing the two family members is initially passed to the first indicating electrode (58), where electroreduction of the first family member produces a first electrical current directly proportional to the concentration of the first family member in the sample. Thereafter, the gas sample is passed through an oxidizing means (4) interconnected between the two indicating electrodes (58, 70), where all of the second family member is converted into the first family member.

Abstract: A conductometric gas analysis cell comprised of a porous Teflon membrane supporting interdigited electrodes separates a thin layer of deionized water from a gas phase to be analyzed. Volatile species in the gas phase pass through the membrane and increase the conductance of the water which results in increased current flow between the interdigited electrodes.

Abstract: A process for purifying water containing fluoride which comprises precipitating fluoride from the water as fluorapatite in the presence of a bed of seeding composition. Fluoride is removed as fluorapatite by having sufficient available calcium for each mole of fluoride present in the water and sufficient available phosphate for each mole of fluoride in the water to form a precipitate which is or converts to sufficient fluorapatite to remove essentially all fluoride from the water.

Abstract: An electrochemical detection system is disclosed for measuring the amount of carbon monoxide or similar oxidizable gases present in a gas phase mixture wherein the gas phase mixture is brought into contact with a liquid electrolyte through a gas-permeable measuring electrode. The improved electrode is formed of a porous membrane of chemically-inert non-wettable material, on one side of which a layer of gold is specially deposited for contact with an electrolyte of a substantially pure aqueous solution of perchloric acid. An electrical readout system is connected to the electrode for deriving a signal from the resulting oxidation current, which corresponds to a quantitative measure of the oxidation of the gas at the electrode-electrolyte interface.

Abstract: A process for purifying waste water containing fluoride which comprises precipitating fluoride from the waste water as fluorapatite. Fluoride is removed as fluorapatite by having sufficient available calcium for each mole of fluoride present in the waste water and sufficient available phosphate for each mole of fluoride in the waste water to form a precipitate which is or converts to sufficient fluorapatite to remove essentially all fluoride from the waste water.

Abstract: Contaminating ions are removed from an aqeuous medium, e.g. hexavalent chromium ions from cooling tower waters, by an electrochemical method which includes formation of an insoluble iron compound or complex of the contaminant ion, utilizing an anode of iron, iron alloy or insoluble iron compound. The electrodes are treated with an acid solution at regular intervals to remove any substances formed on or lodged between the electrodes. The electrolytic cell includes a plurality of closely spaced generally parallel plate electrodes with electric potential applied to the two end electrodes, and an electrode near each end electrode is of a size protecting the end electrode from flux field effects.

Abstract: An electrochemical detection system is disclosed for measuring the amount of carbon monoxide or similar oxidizable gases present in a gas phase mixture wherein the gas phase mixture is brought into contact with a liquid electrolyte through a gas-permeable measuring electrode. The improved electrode is formed of a porous membrane of chemically-inert non-wettable material, on one side of which a layer of gold is specially deposited for contact with an electrolyte of a substantially pure aqueous solution of perchloric acid. An electrical readout system is connected to the electrode for deriving a signal from the resulting oxidation current, which corresponds to a quantitative measure of the oxidation of the gas at the electrode-electrolyte interface.

Abstract: Contaminating ions are removed from an aqueous medium, e.g. hexavalent chromium ions from cooling tower waters, by an electrochemical method which includes formation of an insoluble iron compound or complex of the contaminant ion, utilizing an anode of iron, iron alloy or insoluble iron compound. The electrodes are treated with an acid solution at regular intervals to remove any substances formed on or lodged between the electrodes. The electrolytic cell includes a plurality of closely spaced generally parallel plate electrodes with electric potential applied to the two end electrodes, and an electrode near each end electrode is of a size protecting the end electrode from flux field effects.