173results about How to "Good chemical and thermal stability" patented technology

The invention relates to an aqueous emulsion polymerization of fluorinated monomers using perfluoropolyethers of the following formula (I) or (II). In particular, the perfluoropolyether surfactants correspond to formula (I) or (II)

CF₃—(OCF₂)_m—O—CF₂—X  (I)

wherein m has a value of 1 to 6 and X represents a carboxylic acid group or salt thereof,

CF₃—O—(CF₂)₃—(OCF(CF₃)—CF₂)_z—O-L-Y  (II)

wherein z has a value of 0, 1, 2 or 3, L represents a divalent linking group selected from —CF(CF₃)—, —CF₂— and —CF₂CF₂— and Y represents a carboxylic acid group or salt thereof. The invention further relates to an aqueous dispersion of a fluoropolymer having the aforementioned perfluoropolyether surfactant(s).

The present invention provides an aqueous emulsion polymerization of fluorinated monomers including gaseous fluorinated monomers using a perfluoro ether surfactant as an emulsifier. The perfluoro ether surfactants correspond to formula (I)

R_f—O—CF₂CF₂—X   (I)

wherein R_f represents a linear or branched perfluoroalkyl group having 1, 2, 3 or 4 carbon atoms and X represents a carboxylic acid group or salt thereof. In a further aspect, the invention also provides an aqueous fluoropolymer dispersion comprising the perfluoro ether surfactant and the use of such dispersion in the coating or impregnation of substrates.

A method for maximizing the interfacial properties of magnetoresistive sensors, such as spin valve and GMR sensors used in storage devices, comprises selecting the materials for ferromagnetic layers and for electrically conductive spacers that are interposed between the ferromagnetic layers. The electronegativities of the selected materials are substantially matched so that an absolute value of the differences in electronegativities is minimized. The conductive spacer material provides a relatively low resistivity and a large mean free path. The sensors experience greater chemical and thermal stability, are corrosion resistant, and realize an increased signal output.

The present invention discloses microporous aluminophosphate (AlPO₄) molecular sieve membranes and methods for making and using the same. The microporous AlPO₄ molecular sieve membranes, particularly small pore microporous AlPO-14 and AlPO-18 molecular sieve membranes, are prepared by three different methods, including in-situ crystallization of a layer of AlPO₄ molecular sieve crystals on a porous membrane support, coating a layer of polymer-bound AlPO₄ molecular sieve crystals on a porous membrane support, and a seeding method by in-situ crystallization of a continuous second layer of AlPO₄ molecular sieve crystals on a seed layer of AlPO₄ molecular sieve crystals supported on a porous membrane support. The microporous AlPO₄ molecular sieve membranes have superior thermal and chemical stability, good erosion resistance, high CO₂ plasticization resistance, and significantly improved selectivity over polymer membranes for gas and liquid separations, including carbon dioxide/methane (CO₂/CH₄), carbon dioxide/nitrogen (CO₂/N₂), and hydrogen/methane (H₂/CH₄) separations.

The present invention aims at providing a lead-free glass composition that can be soften and flowed at a firing temperature that is equal to or lower than that of conventional low melting point lead glass. Furthermore, the present invention aims at providing a lead-free glass composition having fine thermal stability and fine chemical stability in addition to that property. The lead-free glass composition according to the present invention is characterized by comprising at least Ag₂O, V₂O₅ and TeO₂ when the components are represented by oxides, wherein the total content ratio of Ag₂O, V₂O₅ and TeO₂ is 75 mass % or more. Preferably, the lead-free glass composition comprises 10 to 60 mass % of Ag₂O, 5 to 65 mass % of V₂O₅, and 15 to 50 mass % of TeO₂.

Disclosed is a secondary battery comprising a cathode, an anode, a separator and an electrolyte, wherein the electrolyte comprises: (a) a eutectic mixture; and (b) a first compound reduced at a higher potential vs. lithium potential (Li/Li+) than the lowest limit of the electrochemical window of the eutectic mixture. The electrolyte uses a eutectic mixture in combination with an additive reduced in advance of the eutectic mixture upon the initial charge to form a solid electrolyte interface (SEI) layer. Therefore, the electrolyte can solve the problem of electrolyte decomposition occurring when using a eutectic mixture alone as an electrolyte for a battery, and thus can prevent degradation of the quality of a battery.

A separator for a wound electrochemical device comprising an expanded polytetrafluoroethylene membrane having pores defining an internal surface area, the internal surface area being substantially coated with a pore coating agent, the separator having a longitudinal modulus of greater than 20,000 lbs/in².

The present invention relates to a hybrid electrode using silver nanowires and graphene, and a preparation method thereof, and more specifically, provides: a hybrid electrode comprising a silver nanowire network and graphene so as to have high light transmittance, improved surface resistance and electrocatalytic reactivity, and flexibility; and a preparation method thereof.

A sulfur dioxide absorbent comprising an ionic liquid comprised of alkyl ether-substituted imidazolium cation and an alkanesulfonate anion moieties possesses a high thermal/chemical stability, high SO₂ absorption rate and low regeneration temperature, and is useful for an effective separation of SO₂ from a combustion exhaust gas mixture or the like.

Catalytic pyrolysis can upcycle waste, e.g., car bumpers, to carbon nanomaterials, preferably using synthetic TiO₂ nanoparticles as catalyst during pyrolysis. Analysis of the carbon nanomaterials shows that, while RGO is produced from thermal pyrolysis of car bumper waste absent TiO₂, RGO spotted with carbon dots is produced in presence of TiO₂ catalyst. Rutile to anatase TiO₂ phase transformation and carbon nanomaterial formation can simultaneously occur during the pyrolysis. Anatase to rutile transformation may occur while TiO₂ absent the bumper material. Such TiO₂-CD-RGO can be used, for example in photocatalytic degradation of organic compounds, such as methylene blue.

The invention relates to a method for separating a tetrahydrofuran-ethyl alcohol-water mixture by a mixed extraction agent and a device suitable for the method. According to the method, dimethyl sulfoxide and ethylene glycol are mixed into a mixed extraction agent in certain proportion, the tetrahydrofuran-ethyl alcohol-water mixture firstly enters a first extraction rectifying tower for separation, a tetrahydrofuran product is obtained at the tower top, tower bottom materials enter a second extraction rectifying tower for separation, an ethyl alcohol product is extracted from the tower top, a tower bottom extraction agent and water mixture enters an extraction agent recovery tower, water is extracted from the tower top, and the extraction agent is recycled after being extracted from the tower bottom. The method has the advantages that the energy consumption is low, the technology is simple, equipment investment is small, the product purity of the separated tetrahydrofuran and ethyl alcohol is high and the like, and the adopted ethylene glycol and dimethyl sulfoxide mixed extraction agent can break three binary azeotropes in the system simultaneously and is easy to recycle and good in chemical heat stability.

A complex crystal phosphor is an inorganic composition containing at least an M element, an Al element, silicon, oxygen, and nitrogen. The inorganic composition has particles having at least two types of crystal phase, and the at least two types of crystal phase include a first crystal phase which is the same as a M₂SiO₄ crystal and a second crystal phase as a β-sialon crystal. Here, M is at least one element selected from the group consisting of (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

The novel porous framework materials (such as metal organic frameworks or covalent organic frameworks) having a wide range of applications, which was designed and developed in an inventive manner to resolve issues with respect to a carrier material in a stationary phase of a conventional chiral chromatographic column in which the carrier material has poor stability, a chiral resolving agent has a low loading rate, and the chiral resolving agent is prone to loss or is applied in a restricted manner. The porous framework material efficiently loads a chiral resolving agent (such as proteins, enzymes, or macrocyclic antibiotics) by means of covalent bonding, adsorption, embedding, and crosslinking, such that a variety of efficient and durable chiral stationary phases are prepared to serve as a novel high-performance chromatographic column filler used for chromatographic chiral separation (such as high-performance liquid chromatography or capillary chromatography). The various chiral stationary phases prepared by applying the above technique have high separation efficiency, high stability, and durability, and have been successfully applied to perform efficient separation of different kinds of chiral materials such as chiral amino acids and a chiral drug. The technique greatly widens the application range and extends the service life of a chiral chromatographic separation column.

The invention discloses a conductive silver paste for a ferrite core inductance and a method for producing the same, wherein the method comprises the following steps that: (1) lead-free glass powder is produced and contains an inorganic additive I which occupies 1-4% of the total quantity of the lead-free glass powder; (2) an organic carrier is produced; (3) superfine silver powder, silver flake, the lead-free glass powder and an inorganic additive II are mixed to produce the powder, the powder is uniformly stirred and then added into the organic carrier, after high-speed stirring and dispersion, the powder is rolled by a three-roller mill to the fineness of lower than 10mum, and is screened by a screen of 200 meshes for producing the conductive silver paste for the ferrite core inductance. The ferrite conductive silver paste can effectively solve the defects of the silver paste for the ferrite core inductance on corrosion resistance, adhesive force and electroplating performance, has good quality, is low in cost, and is an ideal substitute product for lead-bearing paste. The adopted technology can ensure the stability and consistency of the silver paste.

The invention discloses a zirconia honeycomb ceramic body which comprises the raw materials as follows: ceramic raw material, alpha-Al2O3 powder, clay, Mgo, organic cellulose, a binder and ZrO2 powder. The raw materials are mixed evenly by weight percentage and then the binder and moderate amount of water are added, and ball milling, mixed milling and staleness are carried out to prepare pug; the pug is put into a vacuum pugmill for pug milling, and then extrusion molding wet honeycomb ceramic body is put into a far-infrared kiln for drying and shaping into a dry blank; the honeycomb ceramic body is calcined at 1500 DEG C to 1700 DEG C and then cooled and taken out from the kiln. The zirconia honeycomb ceramic body is not only applicable to be used under high temperature environment being over 1500 DEG C in a heating kiln; besides, the heat exchange of the heating kiln is fast and even, thus saving the fuel of the regenerative heating kiln by about 40 percent to 70 percent, promoting yield by more than 15 percent, reducing the emission of NOX gas to be lower than 100ppm and resulting in lower than 150 DEG C gas emission temperature; therefore, the zirconia honeycomb ceramic body greatly improves the burning effect of the regenerative heating kiln, saves fuel and energy, reduces the emission of harmful gases, prolongs the service life of the regenerative heating kiln, improves environment and promotes both economic and social benefits.

The invention provides a silicon-base compound substrate for preparing a nitride semiconductor epitaxial material, and a manufacturing method of the silicon-base compound substrate. The silicon-base compound substrate comprises a silicon monocrystal substrate, a compound stress covariant layer which is formed on the silicon monocrystal substrate and formed by frequently stacking aluminum nitride and a titanium nitride monocrystal thin film material, and a gallium nitride template layer which is formed on the compound stress covariant layer and consists of a gallium nitride monocrystal thin film material. By the silicon-base compound substrate, the crystal lattice and big heat mismatch problems of the silicon-base gallium nitride material are solved; therefore, the preparation cost of a gallium nitride light emitting diode (LED) epitaxial sheet can be reduced greatly; and the silicon-base compound substrate is suitable for application and market popularization.

A process for preparing a mesoporous alumina is described, comprising the following steps:

• a) mixing, in aqueous solution, at least one source of aluminium constituted by an aluminium alkoxide, at least one cationic surfactant and at least one organic solvent selected from methanol and ethanol;
• b) hydrothermally treating the mixture formed in said step a);
• c) drying the solid formed in said step b);
• d) calcining the solid formed in said step c).