Showing papers on "Silver oxide published in 2000"

UV absorbing/reflecting silver oxide layer, and method of making same

Abstract: A silver oxide layer capable of absorbing and/or reflecting significant amounts of ultraviolet (UV) radiation, and a method of making the same. An ion beam including oxygen ions is utilized to densify silver material and transform it into a silver oxide inclusive layer. Due to the densification caused by the bombardment of oxygen ions, the resulting silver oxide layer is capable of absorbing and/or reflecting significant amounts of UV radiation. Such silver oxide layers may be utilized in the context of any suitable coating system where UV absorption and/or reflection is desired.

Synthesis and characterization of functional gradient materials using Indian corals.

Abstract: The partial conversion of coralline hydroxyapatite (HA) into tricalcium phosphate (TCP) catalyzed by the thermal decomposition of silver oxide was investigated. The thermal analysis of HA powder mixed with 5 mol % Ag2O indicated the decomposition of silver oxide to be around 550°C in the presence of HA. Subsequently a functional gradient structure was formed by spreading silver oxide on one surface of the HA compact of diameter 10 mm and then firing at 700°C in air. The X-ray powder diffraction analysis confirmed the formation of α-TCP induced by the Ag2O decomposition. The content of α-TCP of the sintered pellet was found to decrease with the increasing depth from the surface of the pellet. In vitro solubility study in phosphate buffer of pH 7.2 showed the stability of the biphasic material as in between HA and TCP. © 2000 Kluwer Academic Publishers

Long-acting wide-spectrum antiseptic nanometer silver fabirc and its making method

Abstract: Between or on the fabric fibers, superfine silver grains are adhered, which has surface layer of silver oxide and core of metal silver and size of 1-100 nm. The fabric may be used in people's daily life, and may be also used as functional fabric for treating skin infection of traumatic wound and fungi and preventing and treating infection of operational incision.

Quantum confinement effect in heat treated silver oxide nanoparticles

Abstract: Ag2O particles of sizes varying from 6.0 to 16 nm have been prepared by a chemical method. These have been subjected to a heat treatment at temperatures varying from 533 to 623 K. The optical absorption spectra of the heat treated particles dispersed on a glass substrate have been delineated. The absorption peak shows a maximum in wavelength as a function of heat treatment temperature. This has been explained on the basis of formation of nanometer-sized silver layer on the Ag2O particles and the consequential electron confinement within the same.

Regenerable adsorbent for removing sulfur species from hydrocarbon fluids

Abstract: Sulfur species are removed from hydrocarbon fluids by a process that includes contacting the fluid with a solid adsorbent having a porous substrate impregnated with silver oxide. The solid adsorbent preferably comprises activated alumina. The solid adsorbent may be regenerated with a two step process including: 1) heating the adsorbent in an inert atmosphere, preferably an atmosphere containing nitrogen, so that sulfur species are stripped from the adsorbent without oxidizing them, and 2) heating the adsorbent in an oxidizing atmosphere, preferably an atmosphere containing approximately 20% oxygen, so that the silver contained on the adsorbent is re-oxidized, forming silver oxide.

Bactericidal silicon dioxide doped with silver

Abstract: Pyrogenically prepared silica doped with silver or silver oxide is prepared by feeding an aerosol into a flame such as is used for the preparation of pyrogenic silica, mixing the aerosol homogeneously with gas mixture before the reaction, then allowing the aerosol/gas mixture to react in a flame. The resulting pyrogenic silicas doped with silver or silver oxide are separated from the gas stream. The pyrogenic silica doped with silver or silver oxide by means of an aerosol can be used as a bactericidal filler.

Sonoelectrochemistry at highly boron-doped diamond electrodes: silver oxide deposition and electrocatalysis in the presence of ultrasound

Abstract: The use of boron-doped diamond has a considerable impact in electrochemistry owing to the wide potential range accessible, low background currents, extreme hardness, and the ease of chemical modification of diamond surfaces. It is shown here that, although the electrodeposition of silver metal is known to yield very poorly adhering films with a poor electrical contact, a silver oxysalt deposit formed on anodically pre-treated diamond surfaces adheres strongly with good electrical contact. The deposit is stable even in the presence of ultrasound. Voltammetric and XPS studies reveal that the silver oxide deposit, in contrast to the silver metal deposit, is efficiently stripped from the diamond surface by applying a sufficiently negative potential. The silver oxysalt Ag7O8NO3, deposited onto two types of boron-doped diamond electrodes, a 50 μm thick polycrystalline thin film deposited on a tungsten substrate and a polished free standing diamond plate, is shown to act as an electrocatalyst for oxygen evolution and for the oxidation of toluene. This development opens up the possibility of boron-doped diamond being applied as an inert and conducting substrate material for a wide range of oxidic materials, which can then be utilised as active electrocatalysts at high applied potentials.

Solid state electrochemical current source

Abstract: A cathode and a solid state electrochemical cell comprising said cathode, a solid anode and solid fluoride ion conducting electrolyte. The cathode comprises a metal oxide and a compound fluoride containing at least two metals with different valences. Representative compound fluorides include solid solutions of bismuth fluoride and potassium fluoride; and lead fluoride and potassium fluoride. Representative metal oxides include copper oxide, lead oxide, manganese oxide, vanadium oxide and silver oxide.

Quasimolecular stable forms of oxygen on silver surface. Theoretical analysis by the density functional theory method

Abstract: A quantum chemical investigation of possible associative oxygen forms on defective silver surface has been performed with the use of gradient-corrected density functional theory (DFT) in the cluster approximation A surface defect was simulated by a cation vacancy (V) Cluster models (M1: Ag12 and M2: O3Ag12) of an active adsorption site (AS) with a vacancy were chosen on the basis of the structure of high-temperature layered silver oxide The adsorbed layer on the defective surface was simulated by three oxygen atoms For the atomic and associative (molecular) forms, the computations gave two stable structures of the adsorbed layer with C 3V and C 2V symmetry The quasimolecular C 2V structure –Ag–O–O ep –O–Ag– resembling metal ozonides is by 44 kcal/mol more stable than the atomic C 3V structure The C 2V structure is singlet and has an electrophilic epoxidizing oxygen atom O ep A theoretical estimation of the density of states (DOS) in the quasimolecular oxygen form revealed a complex structure below the 4d band Additional DOS peaks in this region are due to associative O–O bonds

Method of cleaning of harmful gas and cleaning apparatus

Abstract: Disclosed is a method for cleaning of the harmful gas, the method comprising mixing harmful gas, discharged from reaction processes using organic metal compounds as the reaction raw materials, with oxygen or air and thereafter bringing the mixture into contact with a catalyst obtained by carrying a noble metal on an inorganic support, a catalyst comprising at least one metal oxide selected from vanadium oxide, chromium oxide, manganese oxide, iron oxide, copper oxide, silver oxide, cobalt oxide and nickel oxide or a catalyst obtained by carrying the metal oxide on an inorganic support, at temperatures between 100° C and 800° C to clean the harmful gas Disclosed also is an apparatus used in the method The invention ensures that harmful components can be purified in an efficient manner without discharging organic compounds and a large amount of carbon dioxide after the harmful gas is purified, requiring no aftertreatment

Antibacterial glass and resin composition containing the same

Abstract: PROBLEM TO BE SOLVED: To provide a method for manufacturing an antibacterial glass that a silver ion is eluded at constant rate even in contact with water and ionic silver is hardly deposited as silver metal, and to obtain a resin composition hardly causing discoloration appearance containing the glass SOLUTION: The glass is a borosilicate based or a phosphate based one which contains 005-50 wt% silver oxide(Ag2O) and is surface-finished with a halide

Darstellung und Charakterisierung des Silber(I,II,III)-oxidclathrates Ag7O8HCO3 / Synthesis and Characterization of the Silver(I,II,III) Oxide Clathrate Ag7O8HCO3

Abstract: The silver(I,II,III) oxide clathrate Ag7O8HCO3 was synthesized by anodic oxidation of silver(I) in a suspension of Ag2CO3 in an aqueous AgF solution. The title compound was characterized by single crystal X-ray diffraction (cubic, Fm3̄m, a = 9.8085(3) Å, Z = 4), scanning electron microscopy, thermal analysis, IR spectroscopy, 1H-solid state-NMR and measurement of the magnetic susceptibility

Active material powder and electrode material for electrode of silver oxide battery and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To provide an electrode material having good fluidity and high rate discharging characteristic in a silver oxide battery SOLUTION: An electrode material is composed of an active material powder for electrode which is such a granule that silver oxide particles having an average particle diameter ranging from 1 to 10 μm are agglutinated, and conductive chemical particles 2 of one kind or two kind or more and/or indicating chemical powders are uniformly dispersed in the granules; and green compact of the powder The electrode material is provided with a fine porosity 3 having an average pore diameter of 003-3 μm, and provided with a grain boundary porosity 4 having an average pore diameter of 1-50 μm between granules

Silver oxide-carbon composite material and active material for positive electrode of silver oxide secondary battery and producing method of silver oxide-carbon composite material

Abstract: PROBLEM TO BE SOLVED: To provide a silver oxide-carbon composite material, capable of raising charge and discharge efficiency and prolonging lifetime of a silver oxide secondary battery and to provide its producing method. SOLUTION: Formation of particle of silver oxide (I) and coating on the surface of the particle with the carbon particle are accomplished by adding alkaline solution to water solution of silver salt, containing a powder with an average diameter for carbon particle of 900 Å or smaller. According to the producing method, since the particle growth of silver oxide (I) (Ag2O) is obstructed by the carbon particle, silver oxide-carbon composite material of a small average diameter coated over whole surface with carbon particles is obtained readily.

Sensor, and plant operation method using the same

Abstract: PROBLEM TO BE SOLVED: To provide a compact and maintenance-free sensor and a power plant operation method using the same. SOLUTION: In the sensor having a cylindrical oxygen ion conductor 1 having a shape closed at one end thereof, a metal body 2 bonded to the unclosed end of the oxygen ion conductor 1, a catalyst 3 being in contact with the inner surface of the oxygen ion conductor 1, a lead wire 4 taken out of the catalyst 3, and a cable for external connection connected to the lead wire 4 electrically, silver oxide is contained in the oxygen ion conductor 1 and the metal body 2.

Bactericide silver doped silica

Abstract: Silver or silver oxide-doped silicic acid is claimed which is produced pyrogenically by flame oxidation or preferably flame hydrolysis. The dopants are added at 0.0001 wt.% to up to 20 wt.%, preferably 1-10000 ppm. The dopant is a salt (mixture) of Ag or a suspension of an Ag compound or metallic Ag or their mixture. The BET surface of the doped oxide is 1-600 (preferably 40-400) m /g. An Independent claim is included for the preparation of a silver or silver oxide pyrogenically doped oxide.

Stainless steel excellent in antibacterial property and its production

Abstract: PROBLEM TO BE SOLVED: To produce stainless steel combining excellent corrosion resistance, antibacterial properties and durability and still having excellent antibacterial properties even if being subjected to surface working including grinding which is widely used at the present time and to provide a method for producing it. SOLUTION: Stainless steel is incorporated with silver or a silver compd. by 0.001 to 0.30 wt.% expressed in terms of Ag or moreover with 0.001 to 1.0 wt.% V, also, into the steel, a part of the silver compd. is dispersed as silver oxide 0.0005 to 1.1×(wt.% Ag) wt.% expressed in terms of the content of silver oxide, and, furthermore, the surface layer of the stainless steel is infiltrated and stuck, preferably, with silver or copper antibacterial componential particles. Preferably, a soln. contg. antibacterial components is applied on the surface of the stainless steel, and, by pressurizing or rubbing, they are infiltrated and stuck therein. As the antibacterial components, silver or a silver compd. is preferable. Moreover, when stainless molten steel is continuously cast, the pouring rate at the time of continuous casting is preferably controlled to 0.8 to 1.6 m/min.

Preparation and Characterization of Silver Ultrafine Particles in AOT Reverse Micelles

Abstract: The silver ultrafine particles with diameters less than 10 run were prepared by the sodium borohydride reduction of aqueous silver nitrate within AOT reverse micelles at 25℃. By the analyses of high-resolution electron microscope, electron diffraction pattern and XRD, the. Resulting particles have been found to be pure fcc silver. The results indicated that the sizes of silver ultrafine particles increased with the increase of the molar ratio of water to AOT (ωo)and with the increase of silver nitrate and sodium borohydride concentrations due to the increases in the number of nuclei formed. However, when sodium borohydride was largely in excess, the aqueous solution became basic after mixing and silver oxide was formed. The increase of AOT concentration only resulted in the increase of the number of silver ultrafine particles fanned but had no significant influence on their particle size. Using an alkane with higher carbon-number as the solvent, it was found that the silver ultrafine particles fanned were larger because of the higher intermicellar potential and exchange rate of reverse micelles. Furthermore, blue-shift phenomenon was observed from the investigation on the UV- VIS absorption spectra of the reverse micelles solutions containing silver ultrafine particles. At 400 1Ul1, a linear relationship between the particle size and the molar absorbance could be correlated.

[Basic study on anti-bacterial urethral catheter. I. Development of a new anti-bacterial coating material for silicon catheters].

Abstract: In order to develop a new anti-bacterial urethral catheter, we studied anti-bacterial and anti-adherent coating material suitable for silicon catheters. Several aspects of various silver compounds were examined, including anti-bacterial activity, chemical property and toxicity. Among silver citrate, silver phosphate and silver oxide, which were found to have excellent anti-bacterial activities, silver citrate was regarded as the material of choice for anti-bacterial coating in terms of durable activity and biological safety. It was also found that several surfactants inhibited bacterial adherence to the surface of silicon catheters. Among them soybean lecithin exhibited excellent anti-adherent activity in a dose dependent manner. Finally, a mixture of silver citrate, soybean lecithin and liquid silicon at the ratio of 2:2:8 was regarded as an ideal anti-bacterial coating material for silicon catheters.

Stainless steel material excellent in antibacterial characteristic, and its production

Abstract: PROBLEM TO BE SOLVED: To obtain a steel material combining excellent corrosion resistance with antibacterial characteristic and exhibiting its excellent antibacterial characteristic even after surface working by incorporating specific amounts of silver oxide into a stainless steel containing specific amounts of Al. SOLUTION: Austenitic, ferritic, and martensitic stainless steels are suitably used as a steel material from the viewpoint of corrosion resistance, and the steel material contains 0.001 to 0.30 wt.% Ag and 0.0005 wt.% to 1.1×(wt.% Ag) wt.% of silver oxide and also contains, preferably, 0.001 to 1.0 wt.% V. It is preferable to regulate the size of the silver oxide to <=500 μm. Further, it is preferable that, at the time of continuously casting a molten stainless steel into a steel stock, the content of S and the casting rate at the time of continuous casting are regulated to <=0.015 wt.% and (0.8 to 1.6) m/min, respectively. The stainless steel material can be suitably used for members to be used, after forming and grinding, for purposes where great importance is placed on the sanitary side in a wet environment such as kitchen and bathtub.

Method for continuously cleaning silver electrolyte and equipment therefor

Abstract: PROBLEM TO BE SOLVED: To provide a method and equipment for cleaning silver electrolyte capable of suppressing amount of silver oxide remaining in sediment at the time of sedimenting and removing impurities such as Cu, Pb, Pd in the silver electrolyte as hydroxides thereof by using silver oxide, and continuously performing the cleaning SOLUTION: Silver oxide is added to the silver electrolyte and both are mixed in the first mixing tank 1, hydroxides generated therein are sedimented in a first sedimentation tank 2, supernatant liquid is guided into a second mixing tank 3, where silver oxide is added and mixed, hydroxides generated therein are sedimented in a second sedimentation tank 4 and the sediment is fed back to the first mixing tank 1 Silver oxide is added into the second mixing tank 3 so as to make Cu concentration in the supernatant liquid in the second sedimentation tank 4 <=005 g/l and silver oxide is added into the first mixing tank 1 so as to make pH of the first mixing vessel 1 in a range 4-6

Method for producing silver oxide and method for producing silver powder

Abstract: PROBLEM TO BE SOLVED: To provide a method for producing silver oxide and silver powder by which the consumption of chemicals and the amount of waste solution can be reduced without generating NOx. SOLUTION: A three-chamber electrolytic cell respectively set with an anion exchange membrane as a diaphragm between an anode chamber and an intermediate chamber and a cation exchange membrane as a diaphragm between a cathode chamber and the intermediate chamber is used, an aqueous solution of salt poured into thee intermediate chamber of the electrolytic cell is electrolyzed by using a silver electrode as an anode, and an aqueous solution of silver obtained from the anode chamber and a solution of caustic alkali obtained from the cathode chamber are reacted to obtain silver oxide. The obtained silver oxide is reduced in an alkali solution by adding a solution of hydrogen peroxide or formalin in the optimum temperature range to form silver powder.