Abstract: Acoustic particle metamaterials in Smart Proppants reflect sound waves at distinct frequency ranges when receiving sounds from an above ground or in-ground source. Sound receivers at separated locations receive the reflected sound waves at distinct times, providing information on location of the Smart Proppants, which are mixed with conventional proppants. The Smart Proppants prevent transmission of waves at precise ranges of frequencies and reflect those waves.

Abstract: A new cement formulation includes a base cement slurry and an admixture of acoustic metamaterial particles, the acoustic metamaterial particles each having a dense inner core and compliant surrounding matrix. The cement formulation exhibits a substantial increase in transmission loss over the base cement slurry at a first frequency, and does not exhibit a substantial increase in transmission loss over the base cement slurry at a second frequency. A new cement interrogation technique involves transmitting acoustic energy at and near the band-gap frequency of an acoustic metamaterial, detecting an acoustic response and analyzing it for band-gap performance involving substantially elevated transmission loss at or near a given first frequency that rapidly falls off at nearby frequencies, determining that the cement formulation is present in regions exhibiting band-gap performance, and determining that the cement formulation is not present and/or has been compromised in regions not exhibiting band-gap performance.

Abstract: A method and composition for polymer-reinforced composite cementitious construction materials is described. In one embodiment, a crosslinking component is mixed with a high molecular weight strengthening component and an inorganic cementitious material. The addition of the mixture to water causes a crosslinked molecular network to form within the hydrated, composite cementitious construction material. Both enhanced flexural strength and improved nail-pull resistance are shown, allowing a reduction in weight of the composite cementitious construction material compared to cementitious construction materials made according to other known methods.

Abstract: An in situ ionic interaction between two additives, one a cationic strength enhancing additive and one an anionic crosslinking additive, is used to improve the mechanical properties of an article formed from a composite material. The composite has a discrete phase bound together with a film of the additives, such as gypsum crystals bound together by a film of substituted starch or cellulose ether.

Abstract: An inorganic-organic composite comprises an inorganic phase, such as gypsum crystals, and a film forming organic phase. The film forming organic phase is selected from substituted starches having a degree of polymerization; degree of substitution and viscosity such that the substituted starches are insoluble in water during mixing but dissolve at a higher processing temperature during forming, setting or drying of the composite. Thus, excessive migration of the substitute starch is prevented and the composite is substantially strengthened.

Abstract: Construction materials containing surface modified reinforcements are used to fabricate composite structures. The composite structures comprise a matrix material and surface modified reinforcements, such as fibers and particulates. The surface modifier may be applied to a fiber surface using conventional sizing equipment and provides a durable film on the fiber. The surface modifier may be selected to have multifunctional properties, for example, increasing fiber pull-out strength, imparting bio-active properties, improving moisture resistance and other desirable properties to the composite structure.

Abstract: A gypsum-based composite structure is prepared from a slurry comprising a mixture of calcium sulfate hemihydrate, a cellulose ether additive other than CMC and an amount of water that is sufficient to form a slurry. The calcium sulfate hemihydrate is hydrated by the water forming a wallboard core reinforced by the cellulose ether additive. The concentration, viscosity grade and degree of substitution of the cellulose ether are selected to give the composite improved nail pull resistance and greater flexural strength.

Abstract: A reinforced wallboard core is prepared from a slurry comprising a mixture of ?-calcium sulfate hemihydrate, a cellulose ether additive other than CMC and an amount of water that is sufficient to form a slurry and resulting in a wallboard density of less than 0.8 g/cc. The ?-calcium sulfate hemihydrate is hydrated by the water forming a wallboard core reinforced by the cellulose ether additive. The cellulose ether, having a molecular weight of at least about 20,000 and a viscosity grade of at least about 100 cps, is selected to give the reinforced wallboard core improved nail pull resistance and greater flexural strength than unreinforced wallboard of the same density. The reinforced wallboard core may be used for reduced-paper wallboard and/or for lightweight wallboard, for example.

Abstract: The present invention discloses a composition of matter for use in wallboard in the construction that has a morphology of pores and a network of interconnected inorganic particles that are coated with a thin layer of organic binder. The process used to produce the wallboard can use either hydrophobic or hydrophilic prepolymers or preferably both to create the desired network of coated inorganic particles. A preferred embodiment uses at least one hydrophobic constituent and a decomposition reaction that produces a gas to form one or more layers or a gradient of the morphology in one or more layers to create wallboard products with superior properties to those wallboard products now known.

Abstract: A reinforced wallboard core is prepared from a slurry comprising a mixture of &bgr;-calcium sulfate hemihydrate, a cellulose ether additive other than CMC and an amount of water that is sufficient to form a slurry and resulting in a wallboard density of less than 0.8 g/cc. The &bgr;-calcium sulfate hemihydrate is hydrated by the water forming a wallboard core reinforced by the cellulose ether additive. The cellulose ether, having a molecular weight of at least about 20,000 and a viscosity grade of at least about 100 cps, is selected to give the reinforced wallboard core improved nail pull resistance and greater flexural strength than unreinforced wallboard of the same density. The reinforced wallboard core may be used for reduced-paper wallboard and/or for lightweight wallboard, for example.

Abstract: A gypsum-based composite structure is prepared from a slurry comprising a mixture of calcium sulfate hemihydrate, a cellulose ether additive other than CMC and an amount of water that is sufficient to form a slurry. The calcium sulfate hemihydrate is hydrated by the water forming a wallboard core reinforced by the cellulose ether additive. The concentration, viscosity grade and degree of substitution of the cellulose ether are selected to give the composite improved nail pull resistance and greater flexural strength.

Abstract: Construction materials containing surface modified reinforcements are used to fabricate composite structures. The composite structures comprise a matrix material and surface modified reinforcements, such as fibers and particulates. The surface modifier may be applied to a fiber surface using conventional sizing equipment and provides a durable film on the fiber. The surface modifier may be selected to have multifunctional properties, for example, increasing fiber pull-out strength, imparting bio-active properties, improving moisture resistance and other desirable properties to the composite structure.

Abstract: A method and composition for polymer-reinforced composite cementitious construction materials is described. In one embodiment, a crosslinking component is mixed with a high molecular weight strengthening component and an inorganic cementitious material. The addition of the mixture to water causes a crosslinked molecular network to form within the hydrated, composite cementitious construction material. Both enhanced flexural strength and improved nail-pull resistance are shown, allowing a reduction in weight of the composite cementitious construction material compared to cementitious construction materials made according to other known methods.

Abstract: The present invention discloses a composition of matter for use in wallboard in the construction that has a morphology of pores and a network of interconnected inorganic particles that are coated with a thin layer of organic binder. The process used to produce the wallboard can use either hydrophobic or hydrophilic prepolymers or preferably both to create the desired network of coated inorganic particles. A preferred embodiment uses at least one hydrophobic constituent and a decomposition reaction that produces a gas to form one or more layers or a gradient of the morphology in one or more layers to create wallboard products with superior properties to those wallboard products now known.