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: 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: 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: 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: 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: The present invention provides an anti-pathogenic air filtration medium comprising a fibrous substrate whose fibers are coated with coating comprising a polymer. The coating provides an environment that is destructive to airborne pathogens. In particular, the filter medium can be used in a building air handling system that both filters the air and eliminates pathogens. The filter medium also can be used to create a new bio-protective gas mask that not only offers protection against chemical warfare agents, but also provides protection against biological pathogens.

Abstract: A composite structure comprises an inorganic discrete phase, an organic matrix phase and an interfacial layer comprising both the inorganic and organic phases. In one process, the inorganic discrete phase is partially dissolved and the precipitated by a chemical reaction forming an interfacial layer having a finite thickness and transitioning from 100% inorganic to 100% organic.

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: A filter media comprises a medium for capturing and neutralizing harmful substances. Methods for fabricating a low-pressure, high efficiency filter media for capturing harmful substances produce filter media having engineered pores that have an engineered pour size dispersion, which may be monodispersed and uniformly arranged. Neutralizing components may be coated on filter media, providing both increased capture efficiency and neutralization of at least one harmful substance, such as harmful pathogens, aerosols, particulates, VOCs, gases and vapors.

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.