Abstract: The invention is directed to use of polystyrene wastes, such as Styrofoam® wastes, and carbon nanofibers to produce a highly hydrophobic composition or composite that can separate oil and water.

Abstract: Polystyrene waste, such as Styrofoam® waste, and carbon nanofibers may be used to produce highly hydrophobic compositions or composites that can separate oil and water. Methods for purifying an aqueous solution may include: passing the aqueous solution, including a hydrophobic organic substance, over or through a surface including a polystyrene-CNF composition, thereby producing an aqueous product including less of the hydrophobic organic substance; and optionally, passing the aqueous product over or through the surface at least one more time.

Abstract: A hybrid photoactive heterojunction including a copper vanadate, Cu2V2O7 (CVO) and a zinc vanadate, Zn2V2O6 (ZVO). Particles of the ZVO are dispersed in particles of the CVO to form the hybrid photoactive heterojunction. The hybrid photoactive heterojunction in the form of a photoactive film includes a substrate which is at least partially coated with the hybrid photoactive heterojunction. A method of photodegrading a dye includes contacting the photoactive film and the dye in a solution and exposing the solution to light. A method of photoelectrochemically oxidizing water includes contacting the photoactive film with water in a solution and exposing the solution to light.

Abstract: A hybrid photoactive heterojunction including a copper vanadate, Cu2V2O7 (CVO) and a zinc vanadate, Zn2V2O6 (ZVO). Particles of the ZVO are dispersed in particles of the CVO to form the hybrid photoactive heterojunction. The hybrid photoactive heterojunction in the form of a photoactive film includes a substrate which is at least partially coated with the hybrid photoactive heterojunction. A method of photodegrading a dye includes contacting the photoactive film and the dye in a solution and exposing the solution to light. A method of photoelectrochemically oxidizing water includes contacting the photoactive film with water in a solution and exposing the solution to light.

Abstract: A composite material of polyurethane foam having a layer of reduced graphene oxide and polystyrene is described. This composite material may be made by contacting a polyurethane foam with a suspension of reduced graphene oxide, drying, and then irradiating in the presence of styrene vapor. The composite material has a hydrophobic surface that may be exploited for separating a nonpolar phase, such as oil, from an aqueous solution.

Abstract: A composite material of polyurethane foam having a layer of reduced graphene oxide and polystyrene is described. This composite material may be made by contacting a polyurethane foam with a suspension of reduced graphene oxide, drying, and then irradiating in the presence of styrene vapor. The composite material has a hydrophobic surface that may be exploited for separating a nonpolar phase, such as oil, from an aqueous solution.

Abstract: A composite material of polyurethane foam having a layer of reduced graphene oxide and polystyrene is described. This composite material may be made by contacting a polyurethane foam with a suspension of reduced graphene oxide, drying, and then irradiating in the presence of styrene vapor. The composite material has a hydrophobic surface that may be exploited for separating a nonpolar phase, such as oil, from an aqueous solution.

Abstract: Composite materials for removing hydrophobic components from a fluid include a porous matrix polymer, carbon nanotubes grafted to surfaces of the porous matrix polymer, and polystyrene chains grafted to the carbon nanotubes. Examples of porous matrix polymer include polyurethanes, polyethylenes, and polypropylenes. Membranes of the composite material may be enclosed within a fluid-permeable pouch to form a fluid treatment apparatus, such that by contacting the apparatus with a fluid mixture containing water and a hydrophobic component, the hydrophobic component absorbs selectively into the membrane. The apparatus may be removed from the fluid mixture and reused after the hydrophobic component is expelled from the membrane. The composite material may be prepared by grafting functionalized carbon nanotubes to a porous matrix polymer to form a polymer-nanotube composite, then polymerizing styrene onto the carbon nanotubes of the polymer-nanotube composite.

Abstract: A hybrid photoactive heterojunction including a copper vanadate, Cu2V2O7 (CVO) and a zinc vanadate, Zn2V2O6 (ZVO). Particles of the ZVO are dispersed in particles of the CVO to form the hybrid photoactive heterojunction. The hybrid photoactive heterojunction in the form of a photoactive film includes a substrate which is at least partially coated with the hybrid photoactive heterojunction. A method of photodegrading a dye includes contacting the photoactive film and the dye in a solution and exposing the solution to light. A method of photoelectrochemically oxidizing water includes contacting the photoactive film with water in a solution and exposing the solution to light.

Abstract: A method for detecting mercury (Hg2+) ions in an aqueous solution is described. The method includes contacting the aqueous solution with a chemosensor to form a mixture; and monitoring a change in a fluorescence emission profile of the chemosensor in the mixture to determine the presence or absence of Hg2+ ions in the aqueous solution. The chemosensor includes pyrene silica nanoparticles where at least one pyrene is bonded to a surface of a silica nanoparticle through an amide bond with a formula of, pyrene-C(?O)NHR-silica nanoparticle, and where R is an alkyl chain.

Abstract: Vapor phase polymerization can be used to synthesize a 3D porous network of polystyrene-containing, branched carbon nanofibers on polyurethane(s), optionally using natural light (NL) initiation. NL styrene polymerization in a confined reactor containing CNF-grafted PU can provide a stable porous network. The NL can vaporize the styrene by increasing the reactor temperature and generate styrene radicals. Without CNF, the polymerization on polyurethane (PU) provides a delicate, fragile surface. Radical styrene in vapor phase can interact with CNF to produce polystyrene branches by generating active sites on CNF, while reinforcing the 3D porous structure. After polymerization, the PU surface area increased from 9 to 184 m2/g and pore size decreased from 2567 to 10 ?. 3D porous networks of NL-assisted PS branched CNF supported PU can provide a hydrophobic, oleophilic surface with a water contact angle of approx 148±3°, rapidly gravity separating hexane and water without external force.

Abstract: Composite materials for removing hydrophobic components from a fluid include a porous matrix polymer, carbon nanotubes grafted to surfaces of the porous matrix polymer, and polystyrene chains grafted to the carbon nanotubes. Examples of porous matrix polymer include polyurethanes, polyethylenes, and polypropylenes. Membranes of the composite material may be enclosed within a fluid-permeable pouch to form a fluid treatment apparatus, such that by contacting the apparatus with a fluid mixture containing water and a hydrophobic component, the hydrophobic component absorbs selectively into the membrane. The apparatus may be removed from the fluid mixture and reused after the hydrophobic component is expelled from the membrane. The composite material may be prepared by grafting functionalized carbon nanotubes to a porous matrix polymer to form a polymer-nanotube composite, then polymerizing styrene onto the carbon nanotubes of the polymer-nanotube composite.

Abstract: A composite of polyurethane foam grafted with carbon nanofibers is described. This composite foam may be made by contacting and drying a polyurethane foam with a suspension of carbon nanofibers and then drying. Additional carbon nanofiber layers may be added with repeated contacting. The composite film has a high surface area of 276 m2/g and a hydrophobic character that may be exploited for separating an oil phase from water.

Abstract: Disclosed is a copper coated stainless-steel hydrophobic mesh and a method for synthesizing the hydrophobic mesh. In the method, a stainless-steel mesh is sonicated in a solution of acetone and ethanol, and then electroplated in a copper solution to form a copper coating on the surface of the mesh. The copper-coated stainless-steel mesh is treated with an oxidizing solution having an oxidizing potential applied to it. The mesh is then washed with water and dried. The copper-coated stainless-steel mesh is then immersed in a lauric acid solution. The mesh is then rinsed with ethanol to remove adsorbed lauric acid. After drying, the so-synthesized copper-coated stainless-steel hydrophobic mesh is characterized in that it has hydrophobic branches of lauric acid.

Abstract: Disclosed is a copper coated stainless-steel hydrophobic mesh and a method for synthesizing the hydrophobic mesh. In the method, a stainless-steel mesh is sonicated in a solution of acetone and ethanol, and then electroplated in a copper solution to form a copper coating on the surface of the mesh. The copper-coated stainless-steel mesh is treated with an oxidizing solution having an oxidizing potential applied to it. The mesh is then washed with water and dried. The copper-coated stainless-steel mesh is then immersed in a lauric acid solution. The mesh is then rinsed with ethanol to remove adsorbed lauric acid. After drying, the so-synthesized copper-coated stainless-steel hydrophobic mesh is characterized in that it has hydrophobic branches of lauric acid.

Abstract: A composite material of polyurethane foam having a layer of reduced graphene oxide and polystyrene is described. This composite material may be made by contacting a polyurethane foam with a suspension of reduced graphene oxide, drying, and then irradiating in the presence of styrene vapor. The composite material has a hydrophobic surface that may be exploited for separating a nonpolar phase, such as oil, from an aqueous solution.

Abstract: Vapor phase polymerization can be used to synthesize a 3D porous network of polystyrene-containing, branched carbon nanofibers on polyurethane(s), optionally using natural light (NL) initiation. NL styrene polymerization in a confined reactor containing CNF-grafted PU can provide a stable porous network. The NL can vaporize the styrene by increasing the reactor temperature and generate styrene radicals. Without CNF, the polymerization on polyurethane (PU) provides a delicate, fragile surface. Radical styrene in vapor phase can interact with CNF to produce polystyrene branches by generating active sites on CNF, while reinforcing the 3D porous structure. After polymerization, the PU surface area increased from 9 to 184 m2/g and pore size decreased from 2567 to 10 ?. 3D porous networks of NL-assisted PS branched CNF supported PU can provide a hydrophobic, oleophilic surface with a water contact angle of approx 148±3°, rapidly gravity separating hexane and water without external force.

Abstract: A composite of polyurethane foam grafted with carbon nanofibers is described. This composite foam may be made by contacting and drying a polyurethane foam with a suspension of carbon nanofibers and then drying. Additional carbon nanofiber layers may be added with repeated contacting. The composite film has a high surface area of 276 m2/g and a hydrophobic character that may be exploited for separating an oil phase from water.

Abstract: The invention is directed to use of polystyrene wastes, such as Styrofoam® wastes, and carbon nanofibers to produce a highly hydrophobic composition or composite that can separate oil and water.

Abstract: A graphene-modified graphite pencil electrode (GPE) system and a method for simultaneous detection of multiple anylates such as dopamine, uric acid, and L-tyrosine in a solution. The electrode system includes a graphene-modified graphite pencil working electrode comprising a graphite pencil base electrode and a layer of three dimensional nanostructured multiwall network forming concave shape structures on the surface of the graphite pencil base electrode, a counter electrode, and a reference electrode. The method comprises contacting the solution with the graphene-modified GPE system and conducting voltammetry, preferably square wave voltammetry, to detect the L-tyrosine concentration in the solution.