64 results about "Intrinsic conductivity" patented technology

A heart valve sewing prosthesis including an intrinsically conductive polymer. The invention includes annuloplasty rings and bands, and sewing rings or cuffs for prosthetic heart valves. Some annuloplasty rings and sewing rings include fabric that is coated with an intrinsically conductive polymer. The coating can be formed over individual filaments or fibers, or on the fabric surface as a surface layer. One intrinsically conductive polymer is polypyrrole. The intrinsically conductive polymer can be doped to facilitate the intrinsic conductivity. Some devices have a polypyrrole surface layer doped with dialkyl-napthalene sulfonate. The intrinsically conductive polymer can be deposited on a fabric using in-situ polymerization of monomeric or oligomeric species, together with a dopant. Animal studies using implanted annuloplasty rings having an intrinsically conductive polymer coating have demonstrated a substantial reduction in pannus formation and inflammatory response.

The invention relates to a composite comprising a weight fraction of single-wall carbon nanotubes and at least one polar polymer wherein the composite has an electrical and/or thermal conductivity enhanced over that of the polymer alone. The invention also comprises a method for making this polymer composition. The present application provides composite compositions that, over a wide range of single-wall carbon nanotube loading, have electrical conductivities exceeding those known in the art by more than one order of magnitude. The electrical conductivity enhancement depends on the weight fraction (F) of the single-wall carbon nanotubes in the composite. The electrical conductivity of the composite of this invention is at least 5 Siemens per centimeter (S/cm) at (F) of 0.5 (i.e. where single-wall carbon nanotube loading weight represents half of the total composite weight), at least 1 S/cm at a F of 0.1, at least 1×10^{−4 S/cm at (F) of 0.004, at least 6×10−9} S/cm at (F) of 0.001 and at least 3×10⁻¹⁶ S/cm (F) plus the intrinsic conductivity of the polymer matrix material at of 0.0001. The thermal conductivity enhancement is in excess of 1 Watt/m-° K. The polar polymer can be polycarbonate, poly(acrylic acid), poly(acrylic acid), poly(methacrylic acid), polyoxide, polysulfide, polysulfone, polyamides, polyester, polyurethane, polyimide, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinyl pyridine), poly(vinyl pyrrolidone), copolymers thereof and combinations thereof. The composite can further comprise a nonpolar polymer, such as, a polyolefin polymer, polyethylene, polypropylene, polybutene, polyisobutene, polyisoprene, polystyrene, copolymers thereof and combinations thereof.

The invention relates to sheet/branch silver-coated copper powder, a green halogen-free low-silver-content economical electrically conductive adhesive capable of replacing traditional electrically conductive adhesives with high silver contents, and a preparing method of the electrically conductive adhesive. The morphology of the sheet/branch silver-coated copper powder is in a sheet shape and/or a branch shape. The silver coating area rate on the surface of copper powder is 90-95%. The content of a zinc-aluminum alloy in the silver-coated copper powder is lower than 15 wt%. The electrically conductive adhesive comprises following raw materials by weight: 60-90% of the sheet/branch silver-coated copper powder, 0-30% of micron order silver power, 6-12% of epoxy resin, 1-8% of an active diluting agent, 1-6% of toughening resin, 1-3% of a curing agent, 0-1% of a curing promoter and 0.5-2% of a coupling agent. The sheet/branch silver-coated copper powder is high in silver coating rate on the surface of Cu and excellent in electrically conductive performance, so that the electrically conductive adhesive prepared from the sheet/branch silver-coated copper powder is excellent in performance, low in cost and good in intrinsic conductivity.

The invention relates to a secondary lithium battery anode composite material, in particular to an oxygen-vacancy-containing lithium ferrous silicate and carbon composite material. The chemical formula of the composite material is Li2FeSiO4-xNy/C, wherein x is more than 0 and less than or equal to 1, y is more than 0 and less than or equal to 0.5, the condition that x is more than or equal to 3y/2 is met, and carbon content is 5-20wt%. The intrinsic conductivity and the lithium ion conductivity inside granules of the composite material are high, and the composite material has excellent performances such as high capacity and high multiplying power. The preparation method of the composite material comprises the steps of: preparing sol from lithium salt, ferrous salt, a silicon source and a carbon source and then carrying out high temperature calcination on the sol twice to obtain granular and oxygen-vacancy-containing lithium ferrous silicate and carbon composite material.

The invention discloses a group VB doping CaCu3Ti4O12 based pressure sensitive material and a preparation method. The general chemical composition formula of the group VB doping CaCu3Ti4O12 based pressure sensitive materia is CaCu3Ti4-xBxO12, wherein B represents one or combination of group VB elements in the periodic table of chemical elements, and x=0.001-1. The preparation method comprises thefollowing steps of compounding calcium carbonate, copper oxide, vanadium pentoxide, niobium pentaoxide and tantalum pentoxide in accordance with the stoichiometric ratio of CaCu3Ti4-xBxO12 (x=0.001-1, and B represents one or combination of group VB elements in the periodic table of chemical elements), ball milling, calcining, secondary ball milling, pelleting, forming, binder removing, high temperature sintering and the like so that Ca, Cu, Ti-O based ceramics with high permittivity and high pressure sensitive feature can be finally prepared. The invention compensates valence changes of copper ions and titanium ions in the sintering process, which can cause low voltage gradient and large leakage current, by partially replacing a +4 Ti element with a +5 element, thereby reducing the intrinsic conductivity of materials and improving the voltage gradient of the materials.

The invention provides a carbide doped porous carbon and a preparation method thereof. The carbide doped porous carbon is prepared from porous carbon and a metal carbide embedded into the porous carbon. The obtained carbide doped porous carbon has the advantages that the void of the porous carbon is mostly centralized in micropores and mesopores, so that the specific surface area of the porous carbon is favorably improved; the metal carbide is positioned inside the porous carbon; the intrinsic conductivity of the porous carbon is improved; the condition that the conductivity of the porous carbon is reduced while the specific surface area is increased is avoided. The embodiment result shows that the carbide doped porous carbon provided by the invention has the specific surface area reaching400 to 1700m<2>/g; compared with a porous carbon material obtained by a traditional method, the carbide doped porous carbon has the advantages that under the condition with the equivalent specific surface area, the conductivity is obviously improved; the defect that the specific surface area is improved by using the conductivity reduction as the cost is avoided.

The invention discloses a carbon nanotube three-dimensional network architecture and a preparation method thereof, and a carbon nanotube/polymer composite material prepared from the carbon nanotube three-dimensional network architecture and having a three-dimensional continuous skeleton structure and a preparation method thereof. The architecture is a three-dimensional network body formed by interconnection of sheet layers composed of carbon nanotubes, and the proportion of the carbon nanotube in the composite material is 0.1 to 10 wt%. The carbon nanotube/polymer composite material with the three-dimensional continuous skeleton structure is constructed by preparing the carbon nanotube architecture with a three-dimensional network by using directional freezing technology, then mixing the carbon nanotube architecture with a polymer and carrying out curing. According to the invention, the carbon nanotube three-dimensional network architecture capable of realizing independent support is used as a conductive additive for a polymer matrix to construct a three-dimensional communicated conductive network in the composite material; and in virtue of good intrinsic conductivity of the carbon nanotube architecture and the characteristics of the inner three-dimensional continuous structure, the conductivity of the polymer composite material is improved.

The present disclosure provides carbon nanotube substrates, and methods of using those substrates, for the treatment and/or amelioration of neurological conditions associated with elevated levels of neural chloride. One aspect of the present disclosure provides a substrate comprising, consisting of or consisting essentially of high-conductivity few-walled CNTs dispersed thereon, wherein the CNTs comprise an intrinsic electrical conductivity of at least 2,500 S/cm. In certain embodiments, the CNTs comprise an intrinsic electrical conductivity in a range of about 1,000 S/cm to about 3,000 S/cm. In an alternative embodiment, the CNTs compromise an intrinsic electrical conductivity in a range of about 1,500 S/cm to about 2,500 S/cm.

The invention belongs to the technical field of energy materials, provides a multilayer silicon/graphene composite lithium battery positive electrode material and a preparation method thereof, and aims to overcome the defects that a silicon cathode has an intense volume effect in the electrochemical lithium storage process, a stable surface solid electrolyte membrane is hard to form and the electric circulation performance is poor as the intrinsic conductivity of the silicon cathode self is low. The multilayer silicon/graphene composite lithium battery positive electrode material provided by the invention comprises foamed nickel, graphene layers and silicon layers, wherein the graphene layers and the silicon layers are arranged on the foamed nickel alternatively; the most top layer is a graphene layer. As a multilayer 'graphene/silicon/graphene'sandwich structure is formed, and silicon powder is wrapped in a layer manner by virtue of high mechanical properties and high conductivity of the graphene, great volume change of the silicon powder in the charge/discharge process can be effectively inhibited, a stable SEI (Solid Electrolyte Interface) membrane can be formed, and the multiplying power property and the circulation stability are improved on premise that a high specific capacity of silicon is maintained; meanwhile, the preparation method of the material is simple in process, low in cost and good in repeatability.

The invention discloses a preparing method of nanometer silicon particles which are doped with trace elements and used for a lithium battery. The doped trace elements are N-type doped crystalline silicon and P-type doped crystalline silicon. The preparing method comprises the steps that firstly, the N-type doped crystalline silicon and the P-type doped crystalline silicon serve as raw materials, acopper pipe serves as a working electrode, a pulse discharge method is adopted for preparing the micron/sub-micron silicon particles doped with the trace elements, and the intrinsic conductivity of silicon is increased by doping the trace elements. Afterwards, the prepared micron/sub-micron silicon particles doped with the trace elements are further nanocrystallized through a high-energy ball milling method, so that the absolute volume change of the silicon particles is reduced. By means of the method, the circulation performance of the silicon material can be improved. The method is simple in preparing technology, convenient to operate and low in cost, and expanded production is facilitated.

A nanotube forming method includes growing a plurality of nanotubes to an intermediate length that is deterministic of nanotube intrinsic conductivity. Individual nanotubes exhibit an effective conductivity, which varies among the plurality of nanotubes. The method includes completing growth of nanotubes exhibiting effective conductivities inside a selected range without completing growth of nanotubes exhibiting effective conductivities outside the selected range. Before completing nanotube growth, the method may further include stopping nanotube growth and screening out nanotubes exhibiting conductivities outside the selected range. The screening out of nanotubes may include deforming or masking nanotubes exhibiting conductivities outside the selected range. Deforming nanotubes may include applying a potential.

The invention discloses a tensile conductive cable and a manufacturing method thereof, which belong to the field of tensile electronics. An elastic matrix and a conductive filler are composite to form the conductive cable. A thermoplastic elastomer is selected as the matrix, and the filler selects a one-dimensional linear or two-dimensional plate-like nano material with high intrinsic conductivity and a high aspect ratio. The manufacturing process comprises steps: the elastic matrix and the conductive filler are mixed to obtain a master batch; then, the obtained blend master batch is used for manufacturing a conductive composite material thin film; and finally, the obtained conductive composite material thin film is cut into ribbons, the ribbons are then twisted into lines, and the tensile conductive cable is manufactured. The conductive composite material cable can be applied to conductive connection of flexible and tensile electronic devices, has advantages of light weight, low cost and the like, has good comprehensive use performance such as high conductivity and high conductive stability under tensile strain, the manufacturing process is simple and free of pollution.

The invention discloses a periodic mesoporous organosilicon material and a preparation method of a polymer composite material thereof. The method comprises the following steps: preparing periodic mesoporous organosilicon with different pore sizes by using organosilicate ester under the regulation and control of a pore former; and importing monomer micromolecules into PMO pores, and performing limited range polymerization to prepare a nonporous high proton conducting material with wide temperature domain and low humidity dependence. The nonporous material can effectively solve the problematic issues of high humidity dependence, fuel penetration and catalyst poisoning and the like can be effectively solved. The material prepared under the regulation and control can maintain the high proton conductivity of 10-2S cm-1 at the relative humidity (RH) 35% and 95%RH, and the intrinsic conductivity has high proton conducting behaviors exceeding 10-3S cm-1 within a temperature range of -40 DEG C to 130 DEG C, and the maximum value reaches 10-2S cm-1, and meanwhile, 77K nitrogen adsorption data show that the nonporous material with a specific surface area of 15.9m2g-1 can be prepared by the regulation and control method.

The invention relates to a method for preparing a boron-doped nano-metal/porous silicon-carbon composite negative electrode based on cut silicon wastes. The method comprises the following steps: removing impurities from cut silicon wastes, and carrying out metal-assisted etching treatment to obtain a nano-metal/porous silicon composite material; mixing the nano-metal/porous silicon composite material with a boron source, and carrying out high-temperature treatment to form substitution doping of silicon by boron; compounding with a carbon material to obtain the boron-doped nano-metal/porous silicon-carbon composite negative electrode. By adding the porous structure of silicon and the carbon material, the volume expansion of silicon can be relieved and cycling stability is increased; the metal particles are physically compounded with silicon on the surface of the silicon substrate, and the boron has the chemical doping synergistic effect of silicon on the atomic scale, so that the intrinsic conductivity of the silicon-based composite material and the electrochemical activity are finally improved, and the boron-doped nano-metal/silicon-carbon composite negative electrode material withhigh charge-discharge specific capacity and long cycle life is prepared.

The invention discloses a high-performance polypyrrole-based ternary composite thermoelectric material and a preparation method thereof. The ternary composite material takes polypyrrole as a matrix and enables a pyrrole monomer to be doped with a graphene nanosheet and then carry out the adsorption and polymerization along the surface of graphene, thereby promoting the adsorption growth of polypyrrole on the surface of graphene as a template, and then the compound and polyaniline are compounded into a polypyrrole/graphene/polyaniline ternary composite thermoelectric material. By adopting the method and the material, the dispersity and compatibility of the composite material can be improved, a special conductive path is formed between the ternary composite materials, the thermoelectric property of the composite material is improved, the defects of low intrinsic conductivity of polypyrrole, high thermal conductivity of graphene and the like are overcome, and by compounding polypyrrole, graphene and polyaniline, the novel preparation method of the polypyrrole-based high-thermoelectric composite material which is simple to operate, environmentally friendly and good in component dispersion uniformity is provided.

The invention provides for polymer structures and their preparation and resulting novel functionalities including open-shell character and high intrinsic conductivity with wide-range tenability. Electrical conductivity can be further modulated by introducing or blending with materials, fillers, dopants, and/or additives. The materials or resultant composites of the invention can be processed by various techniques into different forms to realize multiple applications.