Abstract: A polycrystalline diamond compact (PDC) cutting element includes a substrate and a polycrystalline diamond compact. The substrate comprises a ceramic-metal composite material including hard ceramic particles in a metal matrix. The polycrystalline diamond compact includes interbonded diamond particles. Interstitial material disposed within interstitial spaces between the interbonded diamond particles comprises aluminum and at least one element of the ceramic-metal composite material of the substrate. A method of manufacturing such a PDC cutting element includes forming a mixture including diamond particles and particles of aluminum, and subjecting the mixture and a substrate to a high pressure, high temperature (HPHT) sintering process.

Abstract: A method and apparatus for estimating a concentration of chemicals in a fluid flowing in a fluid passage is disclosed. A sample of the fluid is placed on a substrate comprising a first layer of carbon nanotubes and a second layer of metal nanowires. An energy source radiates the fluid sample with electromagnetic radiation at a selected energy level, and a detector measures an energy level of radiation emitted from the fluid sample in response to the electromagnetic radiation. A processor determines a Raman spectrum of the fluid sample from the energy level of the emitted radiation and estimates the concentration of a selected chemical in the fluid sample based on the Raman spectrum.

Abstract: A polycrystalline compact includes diamond, cubic boron nitride, and at least one hard material, which may be aluminum nitride, gallium nitride, silicon nitride, titanium nitride, silicon carbide, titanium carbide, titanium boride, titanium diboride, and/or aluminum boride. The diamond, the cubic boron nitride, and the hard material are intermixed and interbonded to form a polycrystalline material. An earth-boring tool includes a bit body and a polycrystalline diamond compact secured to the bit body. Methods of fabricating polycrystalline compacts include forming a mixture comprising diamond, non-cubic boron nitride, and a metal or semimetal; encapsulating the mixture in a container; and subjecting the encapsulated mixture to high-pressure and high-temperature conditions to form a polycrystalline material.

Abstract: A suspension for removing hydrocarbons from a subterranean formation includes a fluid comprising at least one of water, brine, steam, carbon dioxide, a light hydrocarbon, and an organic solvent; and a plurality of nanoparticles dispersed with the fluid. Nanoparticles of the plurality comprise silica and carbon. A method includes forming a plurality of nanoparticles and dispersing the plurality of nanoparticles with a fluid to form a suspension comprising the nanoparticles. A method of recovering a hydrocarbon material includes introducing a suspension into a subterranean formation containing hydrocarbons, forming a stabilized emulsion of the suspension and the hydrocarbons within the subterranean formation; and removing the emulsion from the subterranean formation. The suspension comprises a plurality of nanoparticles, and at least some nanoparticles of the plurality comprise silica and carbon.

Abstract: A method of recovering hydrocarbons comprises introducing a suspension comprising nanoparticles to a material and contacting surfaces of the material with the suspension. After introducing the suspension comprising the nanoparticles to the material, the method further includes introducing at least one charged surfactant to the material and removing hydrocarbons from the material. Accordingly, in some embodiments, the nanoparticles may be introduced to the material prior to introduction of the surfactant to the material. Related methods of recovering hydrocarbons from a material are also disclosed.

Abstract: In a composition including a plurality of coated diamond nanoparticles, each diamond nanoparticle may have at least one silane functional group covalently bonded to a surface thereof. A method of forming coated diamond nanoparticles may include functionalizing surfaces of diamond nanoparticles with at least one of a fluorine-containing compound and an oxidant; dispersing the functionalized diamond nanoparticles in a solvent comprising a silane functional group; and forming covalent bonds between the silane functional group and the diamond nanoparticles. A method of forming a diamond coating may include depositing the diamond nanoparticles over a substrate.

Abstract: Method of fabricating polycrystalline diamond include functionalizing surfaces of diamond nanoparticles with fluorine, combining the functionalized diamond nanoparticles with a polymer to form a mixture, and subjecting the mixture to high pressure and high temperature (HPHT) conditions to form inter-granular bonds between the diamond nanoparticles. A green body includes a plurality of diamond nanoparticles functionalized with fluorine, and a polymer material interspersed with the plurality of diamond nanoparticles. A method of forming cutting element includes functionalizing surfaces of diamond nanoparticles with fluorine, and combining the functionalized diamond nanoparticles with a polymer to form a mixture. The mixture is formed over a body, and the mixture and the body are subjected to HPHT conditions to form inter-granular bonds between the diamond nanoparticles and secure the bonded diamond nanoparticles to the body.

Abstract: A suspension for removing hydrocarbons from a subterranean formation includes a fluid comprising at least one of water, brine, steam, carbon dioxide, a light hydrocarbon, and an organic solvent; and a plurality of nanoparticles dispersed with the fluid. Nanoparticles of the plurality comprise silica and carbon. A method includes forming a plurality of nanoparticles and dispersing the plurality of nanoparticles with a fluid to form a suspension comprising the nanoparticles. A method of recovering a hydrocarbon material includes introducing a suspension into a subterranean formation containing hydrocarbons, forming a stabilized emulsion of the suspension and the hydrocarbons within the subterranean formation; and removing the emulsion from the subterranean formation. The suspension comprises a plurality of nanoparticles, and at least some nanoparticles of the plurality comprise silica and carbon.

Abstract: A thermoelectric material includes a polymer matrix and a plurality of partially coated particles dispersed within the polymer matrix. Each particle of the plurality has a discontinuous coating of metal on a carbon-based material. A method includes dispersing functionalized particles comprising a carbon-based material in a solvent; providing a metal salt in the solvent; and forming a plurality of distinct metal volumes on a surface of the functionalized particles to form partially coated particles. The distinct metal volumes are thermally insulated from other volumes of the plurality. A composition of matter includes a discontinuous coating of metal on a surface of a carbon-based material. The carbon-based material is selected from the group consisting of graphene oxide and functionalized carbon nanotubes.

Abstract: A method of recovering hydrocarbons from a subterranean formation comprises introducing a suspension comprising at least one of silica nanoparticles or aluminum silicate nanoparticles into a subterranean formation and contacting surfaces of the subterranean formation with the suspension to form a layer of the at least one of silica nanoparticles or aluminum silicate nanoparticles on at least some surfaces of the subterranean formation. After introducing the suspension comprising the at least one of silica nanoparticles or aluminum silicate nanoparticles into the subterranean formation, the method further includes introducing a solution comprising at least one anionic surfactant into the subterranean formation and extracting hydrocarbons from the subterranean formation. Accordingly, in some embodiments, the nanoparticles may be introduced into the subterranean formation prior to introduction of the surfactant into the subterranean formation.

Abstract: A method of extracting hydrocarbons from a subterranean formation comprises forming a suspension comprising reactive particles and a carrier fluid. The suspension is introduced into a subterranean formation containing a hydrocarbon material. At least a portion of the reactive particles are exothermically reacted with at least one other material within the subterranean formation to form a treated hydrocarbon material from the hydrocarbon material. The treated hydrocarbon material is extracted from the subterranean formation. An additional method of extracting hydrocarbons from a subterranean formation, and a method of treating a hydrocarbon material within a subterranean formation are also described.

Abstract: A system and method for estimating a concentration of monoethanolamine (MEA) in a fluid. A substrate for supporting a sample of the fluid during testing includes a carbon nanotube mat layer, a silver nanowire layer disposed on the carbon nanotube mat layer, and a chemical enhancer layer disposed on the silver nanowire layer. A sample of the fluid is placed on the substrate, and the fluid sample is radiated with electromagnetic radiation at a selected energy level. A detector measures a Raman spectrum emitted from the sample in response to the electromagnetic radiation. A processor estimates the concentration of MEA in the sample from the Raman spectrum and adds a corrosion inhibitor to the fluid in an amount based on the estimated concentration of MEA to reduce the concentration of MEA in the fluid.

Abstract: A method of determining a condition within a wellbore. The method comprises introducing a tubular member in a wellbore extending through a subterranean formation, the tubular member comprising a downhole article including a deformable material disposed around a surface of the tubular member, electrically conductive elements dispersed within the deformable material. The method includes measuring at least one electrical property of the deformable material. At least one of water ingress into the wellbore or an amount of expansion of the deformable material is determined based on the at least one measured electrical property. Related downhole systems and other related methods are also disclosed.

Abstract: A method of extracting hydrocarbons from a subterranean formation comprises forming a suspension comprising reactive particles and a carrier fluid. The suspension is introduced into a subterranean formation containing a hydrocarbon material. At least a portion of the reactive particles are exothermically reacted with at least one other material within the subterranean formation to form a treated hydrocarbon material from the hydrocarbon material. The treated hydrocarbon material is extracted from the subterranean formation. An additional method of extracting hydrocarbons from a subterranean formation, and a method of treating a hydrocarbon material within a subterranean formation are also described.

Abstract: Methods of determining a pH of a wellbore fluid within a wellbore in communication with a subterranean formation comprise introducing carbon quantum dots into a wellbore fluid, exposing the wellbore fluid to radiation from an electromagnetic radiation source, and measuring at least one fluorescence property of the carbon quantum dots within the wellbore fluid to determine a pH of the wellbore fluid. Related methods of determining a pH of a fluid within a wellbore extending through a subterranean formation are also disclosed.

Abstract: A filter membrane includes carbon nanotubes and carbon nitride nanoparticles. Inter-particle atomic interactions between the carbon nanotubes and the carbon nitride nanoparticles bind the carbon nanotubes and the carbon nitride nanoparticles together. A filter cartridge includes such a filter membrane disposed within an outer housing between a fluid inlet and a fluid outlet such that fluid passing through the outer housing between the fluid inlet and the fluid outlet passes through the filter membrane. Such filter membranes may be formed by dispersing carbon nanotubes and carbon nitride nanoparticles in a liquid to form a suspension, and passing the suspension through a filter to deposit the nanotubes and nanoparticles on the filter. Liquid may be filtered by causing the liquid to pass through such a filter membrane.

Abstract: A method of making a thin film substrate involves exposing carbon nanostructures to a crosslinker to crosslink the carbon nanostructures. The crosslinked carbon nanostructures are recovered and disposed on a support substrate. A thin film substrate includes crosslinked carbon nanostructures on a support substrate. The crosslinked carbon nanostructures have a crosslinker between the carbon nanostructures. A method of performing surface enhanced Raman spectroscopy (SERS) on a SERS-active analyte involves providing a SERS-active analyte on such a thin film substrate, exposing the thin film substrate to Raman scattering, and detecting the SERS-active analyte.

Abstract: A method of fabricating a diamond compact includes functionalizing surfaces of diamond nanoparticles with fluorine; combining the functionalized diamond nanoparticles with a non-group-VIII metal to form a particle mixture; and subjecting the particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular bonds between the diamond nanoparticles. A cutting element for an earth-boring tool includes a plurality of grains of diamond material; a plurality of diamond nanoparticles bonded to the plurality of grains of diamond material; and a non-group-VIII metal fluoride disposed within interstitial spaces between the grains of diamond material and the plurality of diamond nanoparticles. The cutting element is substantially free of a metal-solvent catalyst.

Abstract: An initiator nanoconstituent comprises a nanoparticle covalently bonded to a group having a free radical. The nanoparticle may be bonded to the group via an ether group or an amide group. The initiator nanoconstituent may be formed in situ, in a mixture comprising an elastomer material to be crosslinked. The initiator nanoconstituent is formed from an organic nanoconstituent compound that includes the nanoparticle and an organic group that does not include a free radical at the time the mixture is formed. At least one chemical bond of the organic nanoconstituent compound may be ruptured, in situ, to form the initiator nanoconstituent, which may then bond with polymer molecules of the elastomer material and form a crosslinked elastomer material. Downhole tools or components thereof may include such crosslinked elastomer material.

Abstract: A method of stabilizing one or more clays within a subterranean formation comprises forming at least one treatment fluid comprising anionic silica particles, cationic silica particles, and at least one base material. The at least one treatment fluid is provided into a subterranean formation containing clay particles to attach at least a portion of the anionic silica particles and the cationic silica particles to surfaces of the clay particles and form stabilized clay particles. A method of treating one or more clays contained within a subterranean formation, and a treatment fluid for a subterranean formation.