Abstract: This invention provides cement-based material system for the self-sensing of the force (compressive, tensile, flexural, shear, torsional, and combinations thereof) exerted on the cement-based material. It also provides cement-based material system for weighing and a method of the self-sensing. No particular admixture is required in the cement-based material. The measurement involves using two electrodes on the same surface of the cement-based material. The force to be sensed is exerted on the cement-based material, particularly on a part of the material surface between the electrodes. The capacitance measured between the two electrodes serves as an indicator of the force. This invention also provides a method of the self-sensing of force exerted on a cement-based material.

Abstract: This invention provides systems and method for monitoring three-dimensional printing of printing material. A system comprises two coplanar and electrically conductive electrodes and a substrate, which provides a printing surface. The proximate edges of the electrodes, which are on the surface, are separate by a distance ranging from 5 mm to 300 mm. Each electrode is smaller in area than the substrate. The system also comprises a plurality of layers, which are formed layer-by-layer by the printing, and are derived from the printing material. The electrodes are electrically oppositely charged, as enabled by an alternating electric current between the two electrodes. The current partly flows in the layers. The two electrodes exhibit between them a capacitance ranging from 0.1 pF to 10 nF.

Abstract: This invention provides cement-based material system for the self-sensing of the force (compressive, tensile, flexural, shear, torsional, and combinations thereof) exerted on the cement-based material. It also provides cement-based material system for weighing and a method of the self-sensing. No particular admixture is required in the cement-based material. The measurement involves using two electrodes on the same surface of the cement-based material. The force to be sensed is exerted on the cement-based material, particularly on a part of the material surface between the electrodes. The capacitance measured between the two electrodes serves as an indicator of the force. This invention also provides a method of the self-sensing of force exerted on a cement-based material.

Abstract: This invention provides systems and method for monitoring three-dimensional printing of printing material. A system comprises two essentially coplanar and electrically conductive electrodes and a substantially electrically non-conductive substrate, which provides a printing surface. The proximate edges of the electrodes, which are on the surface, are essentially parallel and separate by a distance ranging from 5 mm to 300 mm. Each electrode is substantially smaller in area than the substrate. The system also comprises a plurality of layers, which are formed layer-by-layer by the printing, and are derived from the printing material. The electrodes are electrically oppositely charged, as enabled by an alternating electric current between the two electrodes. The current partly flows in the layers. The two electrodes exhibit between them a capacitance ranging from 0.1 pF to 10 nF. The capacitance is essentially in a direction parallel to the surface and substantially perpendicular to the proximate edges.

Abstract: This invention provides a hybrid material that exhibits strength, stiffness and ability to resist high temperatures. This hybrid material essentially consists of component A and component B. Component A is selected from the group consisting of inorganic compounds, oxides, carbides, nitrides, borides, and combinations thereof. Component B is selected from the group comprising elemental carbon, inorganic compounds, oxides, carbides, nitrides, borides, and combinations thereof. Component B comprises a plurality of units, each of the units substantially exhibiting a shape, such that this shape substantially exhibits a long dimension and a short dimension, with the short dimension being in a direction that is essentially perpendicular to the direction of the long dimension and the short dimension being in the range from 0.1 nm to 0.5 ?m. Each of the units of component B is substantially in contact with and substantially bonded to at least one of the units of component A.

Abstract: This invention provides a material for vibration damping, said material comprising a composite, said composite comprising a cement matrix, and exfoliated graphite that is distributed in said composite. Said cement is preferably hydraulic cement containing calcium silicate. Said exfoliated graphite exhibits a morphology that enables the physical units of exfoliated graphite to connect mechanically. The proportion of exfoliated graphite in the composite is high enough for the exfoliated graphite to connect mechanically in the presence of cement. The proportion of cement in the composite is high enough for the cement to form a continuous matrix in the composite. This invention also provides a material for vibration damping, said material comprising a composite, said composite comprising a continuous cement matrix and a graphite network, said network being mechanically connected.

Abstract: The present invention relates to strain or stress sensors which include a first planar conductive element, a second planar conductive element, and a flexible graphite sheet sandwiched between the first and second planar conductive elements. The flexible graphite sheet includes a mass of expanded graphite particles compressed together in the absence of a binder. Prior to compression, the expanded graphite particles have a c direction dimension which is at least 80 times that of the graphite particles from which the expanded particles are formed. The sensor is configured so that compression of the sensor causes a change in resistance which can be correlated to strain or stress. The present invention also relates to a strain or stress sensor which includes a polymeric composite, a first electrically conductive lead connected to a first point on or in the polymeric composite, and a second electrically conductive lead connected to a second point on or in the polymeric composite.

Abstract: This invention relates to a mesoporous carbon material in the form of filaments having a high surface area. A process is also provided to produce mesoporous carbon material of high surface area. The process comprises drying a carbon material, surface oxidizing the dried material, stabilizing the surface oxidized material, and activating the stabilized material to produce a highly activated, mesoporous material.

Abstract: A material including filaments, which include a metal and an essentially coaxial core, each filament having a diameter less than 6 .mu.m, each core being essentially carbon, displays high effectiveness for shielding electromagnetic interference (EMI) when dispersed in a matrix to form a composite material. This matrix is selected from the group consisting of polymers, ceramics and polymer-ceramic combinations. This metal is selected from the group consisting of nickel, copper, cobalt, silver, gold, tin, zinc, nickel-based alloys, copper-based alloys, cobalt-based alloys, silver-based alloys, gold-based alloys, tin-based alloys and zinc-based alloys. The incorporation of 7 percent volume of this material in a matrix that is incapable of EMI shielding results in a composite that is substantially equal to copper in EMI shielding effectiveness at 1-2 GHz.

Abstract: A new strain/stress sensor based on the concept of reversible crack opening in a composite material. Crack opening increases the electrical resistance, which is the signal provided by the sensor. The new technology is manifested in concrete and mortar containing electrically conducting short fibers (e.g., carbon fibers and steel fibers). Carbon fibers serve to greatly decrease the crack height so that apparently reversible crack opening occurs. The crack opening is accompanied by fiber pull-out, resulting in fiber-matrix contact resistivity increase, thus allowing sensing under cyclic as well as static loading. A part of the resistance change is irreversible, so it provides memory of the first deformation.

Abstract: The present invention relates to a particulate carbon complex made from a porous, particulate carbon substrate and a plurality of carbon filaments each having a first end attached to the porous, particulate carbon substrate and a second end distal from substrate. The complex is capable of transferring electrical current at a density of 350 to 10,000 mA/cm.sup.2 for a Fe.sup.+2 /Fe.sup.+3 oxidation/reduction electrochemical reaction couple carried out in an aqueous electrolyte solution containing 6 mM potassium ferrocyanide and 1M potassium nitrate. The complex is prepared by providing a porous, particulate carbon substrate with impregnated metal catalyst and contacting the substrate with a gaseous carbonaceous material under conditions effective to form a plurality of carbon filaments on the substrate. Generally, the complex includes particles of metal catalyst material at the end of the filaments distal from the substrate.

Abstract: A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.

Abstract: A binder for binding reinforcement materials is provided in which an aluminum and/or Group IIa-containing compound is combined, in a liquid, with a phosphorus-containing compound wherein said binder has a ratio of phosphorus to aluminum and/or Group IIa ions of 14 to 34, preferably 20 to 30. The binder is useful in binding reinforcement materials, particularly suited for preparing preforms for making metal matrix composite materials.

Abstract: A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting-a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.

Abstract: A composite article comprising a resin matrix containing both carbon fibers and a tin alloy. In the preferred embodiment, fiber containing layers within the matrix are separated by alloy containing layers within the matrix.The invention further includes the method of manufacturing the composite articles by impregnating layers of carbon fibers with a resin to form impregnated sheets, spreading alloy powder between the sheets and compression molding the resulting article at a sufficient temperature and pressure for a sufficient time to melt the alloy and cure the resin.

Abstract: A solder joint between two surfaces comprising an intermediate composite solder preform, said preform comprising metal coated carbon fibers contained in a metal matrix, said fibers comprising from 2 to 80 percent by volume of the composite, said metal matrix melting at a temperature below 600.degree. C. and containing at least 15 weight percent tin.

Abstract: A superconducting laminate having at least one layer of metal and at least one layer of superconducting material. The metal layer and the superconducting layer are bonded. The metal later may also include carbon fibers from various precursors. The superconductor may be a composite material. The invention also includes a method of making the laminates.

Abstract: Portland cement concrete-carbon fiber structure displays high tensile and flexural strengths, low electrical resistivity and high electromagnetic interference shielding effectiveness. The structure comprises cement concrete having a small predetermined proportion of carbon fibers dispersed therein. During the fabrication of the structure, there is added thereto an accelerating admixture comprising polyethanolamine and one of metal sulfate plus metal aluminum sulfate or metal nitrite plus metal chloride. The accelerating admixture comprises a small predetermined weight percentage of the cement in the structure. Additional improvements are obtained by using a small proportion of water-reducing agents.

Abstract: Composites of graphite dispersed in a solid matrix of a polymeric resin, wherein intercalated graphite flakes are mixed with a liquid polymeric resin and exfoliated in-situ in the liquid resin during the curing of the resin before complete solidifcation of the resin.

Abstract: Graphite fibers are exfoliated to produce a fiber of reduced density, increased diameter, and flexibility with respect to graphite fibers prior to exfoliation. The fibers may also be used in composite articles. A method of producing exfoliated graphite fibers intercalates the fibers and then exfoliates the intercalated fiber by heating.