A method for preparing a graphene-nanosheets based concrete additive is disclosed. The method comprises mixing Polycarboxylate ether A (PCE-A) to a retarder - based salt solution to obtain a retarder-based Polycarboxylate ether A solution. In the next step, a retarder based PCE solution is obtained by adding Polycarboxylate ether B to the retarder based Polycarboxylate ether A solution to which graphene nanosheets are added. Further, an air entrainment agent is added to graphene nanosheets based PCE solution and further mixed to obtain the graphene nanosheets based concrete additive.

A carbon nanotube (CNT) hybrid material that includes a blend comprising a catalyst supported on at least one of a metal, metalloid, metal oxide or carbon support, and at least one material selected from the group of materials consisting of: cementitious materials, materials used in the production of cementitious materials, and materials used to enhance cementitious materials, and CNT on the blend.

Methods for making carbon-fiber reinforced geopolymer composites are provided. The methods produce metakaolin-based geopolymer composites in which multiwalled carbon nanotubes and/or carbon nanofibers are well dispersed in an metakaolin-based geopolymer matrix. The mixing protocols of the methods used to produce carbon-fiber reinforced geopolymer composites produce composites with reduced porosity, high elastic moduli, high strength, and/or high fracture toughness.

Methods for making carbon-fiber reinforced geopolymer composites are provided. The methods produce metakaolin-based geopolymer composites in which multiwalled carbon nanotubes and/or carbon nanofibers are well dispersed in an metakaolin-based geopolymer matrix. The mixing protocols of the methods used to produce carbon-fiber reinforced geopolymer composites produce composites with reduced porosity, high elastic moduli, high strength, and/or high fracture toughness.

Hardenable inorganic systems such as cements, plasters, ceramics or liquid silicates, usable for example in the building trade, construction industry or oil drilling industry. The insertion of carbonaceous nanofillers, such as carbon nanotubes, for reinforcing mechanical properties and improving such systems. A method for producing a master mixture including at least one superplasticizer and carbonaceous nanofillers at a mass ratio of between 0.1% and 25%, preferably between 0.2% and 20%, in relation to the total weight of the master mixture, and also to said master mixture thus obtained and to the use thereof in a hardenable inorganic system with a view to producing materials with improved properties. The disclosure applies to the construction industry, the building trade and the oil drilling industry.

Hardenable inorganic systems such as cements, plasters, ceramics or liquid silicates, usable for example in the building trade, construction industry or oil drilling industry. The insertion of carbonaceous nanofillers, such as carbon nanotubes, for reinforcing mechanical properties and improving such systems. A method for producing a master mixture including at least one superplasticizer and carbonaceous nanofillers at a mass ratio of between 0.1% and 25%, preferably between 0.2% and 20%, in relation to the total weight of the master mixture, and also to said master mixture thus obtained and to the use thereof in a hardenable inorganic system with a view to producing materials with improved properties. The disclosure applies to the construction industry, the building trade and the oil drilling industry.

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement, activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature, reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent, and sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.

A low carbon footprint material is used to decrease the carbon dioxide emission for production of a high carbon footprint substance. A method of forming composite materials comprises providing a first high carbon footprint substance; providing a carbon nanomaterial produced with a carbon-footprint of less than 10 unit weight of carbon dioxide (CO.sub.2) emission during production of 1 unit weight of the carbon nanomaterial; and forming a composite comprising the high carbon footprint substance and from 0.001 wt % to 25 wt % of the carbon nanomaterial, wherein the carbon nanomaterial is homogeneously dispersed in the composite to reduce the carbon dioxide emission for producing the composite material relative to the high carbon footprint substance.

A low carbon footprint material is used to decrease the carbon dioxide emission for production of a high carbon footprint substance. A method of forming composite materials comprises providing a first high carbon footprint substance; providing a carbon nanomaterial produced with a carbon-footprint of less than 10 unit weight of carbon dioxide (CO.sub.2) emission during production of 1 unit weight of the carbon nanomaterial; and forming a composite comprising the high carbon footprint substance and from 0.001 wt % to 25 wt % of the carbon nanomaterial, wherein the carbon nanomaterial is homogeneously dispersed in the composite to reduce the carbon dioxide emission for producing the composite material relative to the high carbon footprint substance.

A method of producing dispersed of high quality graphene/graphite oxides in a powder matrix to then be reacted to form a composite. Where the powders have similar hydrophobicity and the graphene/graphite oxides has minimal surface oxidation or minimal epoxy group and where the powders are sonically mixed.