Abstract: The present disclosure provides a nanostructured cellulose membrane system with high porosity, and methods for making same. The cellulose membrane system includes carboxylate-functionalized cellulose nanofibers combined with a cellulose microfiber scaffold, which are attached by a crosslinking reaction between the nanofibers and/or between the nanofibers and the microfiber scaffold.

Abstract: Membranes suitable for use in membrane distillation are provided. Such membranes may include nano-fibrous layers with adjustable pore sizes. The membranes may include a hydrophobic nanofibrous scaffold and a thin hydrophilic protecting layer that can significantly reduce fouling and scaling problems.

Abstract: Nanoparticle-fibrous membrane composites are provided as tunable interfacial scaffolds for flexible chemical sensors and biosensors by assembling gold nanoparticles (Au NPs) in a fibrous membrane. The gold nanoparticles are functionalized with organic, polymeric and/or biological molecules. The fibrous membranes may include different filter papers, with one example featuring a multilayered fibrous membrane consisting of a cellulose nanofiber (CN) top layer, an electrospun polyacrylonitrile (PAN) nanofibrous midlayer (or alternate material), and a non-woven polyethylene terephthalate (PET) fibrous support layer, with the nanoparticles provided on the fibrous membranes through interparticle molecular/polymeric linkages and nanoparticle-nanofibrous interactions. Molecular linkers may be employed to tune hydrogen bonding and electrostatic and/or hydrophobic/hydrophilic interactions to provide sensor specificity to gases or liquids. The sensors act as chemiresistor-type sensors.

Abstract: Nanoparticle-fibrous membrane composites are provided as tunable interfacial scaffolds for flexible chemical sensors and biosensors by assembling gold nanoparticles (Au NPs) in a fibrous membrane. The gold nanoparticles are functionalized with organic, polymeric and/or biological molecules. The fibrous membranes may include different filter papers, with one example featuring a multilayered fibrous membrane consisting of a cellulose nanofiber (CN) top layer, an electrospun polyacrylonitrile (PAN) nanofibrous midlayer (or alternate material), and a nonwoven polyethylene terephthalate (PET) fibrous support layer, with the nanoparticles provided on the fibrous membranes through interparticle molecular/polymeric linkages and nanoparticle-nanofibrous interactions. Molecular linkers may be employed to tune hydrogen bonding and electrostatic and/or hydrophobic/hydrophilic interactions to provide sensor specificity to gases or liquids. The sensors act as chemiresistor-type sensors.

Abstract: Membranes are provided for use in reverse osmosis applications. Such membranes include a nanofibrous scaffold in combination with a barrier layer. The barrier layer is formed of a polymeric matrix having functionalized cellulose nanofibers incorporated therein. The membranes may, in embodiments, also include a substrate.

Abstract: The present disclosure provides cellulose/metal composites and their use in removing impurities from liquids, including water. Carboxylated nanocelluloses are combined with metal ions and the resulting composite may be contacted with a liquid, including water, to remove impurities therefrom.

Abstract: A method of treating contaminated water, such as wastewater, with carboxylated cellulose to remove ammonium and nitrogen-containing impurities is claimed. Carboxylated cellulose extracted by nitro-oxidation has negatively-charged functionality and forms an aggregate when exposed to positively-charged impurities in contaminated water. The aggregate, nitrogen-containing impurities, and by-products from the nitro-oxidation process can be isolated to provide a fertilizer or fertilizer component.

Abstract: The present disclosure provides methods for producing carboxylated nanocelluloses. Compared with conventional methods, the methods of the present disclosure are simple and cost-effective in the production of carboxylated (or carboxy) nanocelluloses, in embodiments nanofibers and/or nanowhiskers, directly from raw biomass, including lignocellulose wood, non-wood sources, non-lignocellulose wood, lignocellulose or pure cellulose. The carboxy groups on the surface of nanocellulose thus produced can then be easily modified into functional derivatives such as amide, acetate, ether, ester, etc. The resulting nanocelluloses may be used to form purifying agents and/or filters to remove impurities from wastewater.

Abstract: Membranes suitable for use in membrane distillation are provided. Such membranes may include nano-fibrous layers with adjustable pore sizes. The membranes may include a hydrophobic nanofibrous scaffold and a thin hydrophilic protecting layer that can significantly reduce fouling and scaling problems.

Abstract: Membranes suitable for use in membrane distillation are provided. Such membranes may include nano-fibrous layers with adjustable pore sizes. The membranes may include a hydrophobic nano fibrous scaffold and a thin hydrophilic protecting layer that can significantly reduce fouling and scaling problems.

Abstract: Membranes are provided for use in reverse osmosis applications. Such membranes include a nanofibrous scaffold in combination with a barrier layer. The barrier layer is formed of a polymeric matrix having functionalized cellulose nanofibers incorporated therein. The membranes may, in embodiments, also include a substrate.

Abstract: Water filtration membranes are provided. Such membranes include polysaccharide fibers that have been modified to possess thiol groups thereon, resulting in materials that effectively bind heavy metal ions. The resulting fibers may be used by themselves or applied to a scaffold to form a membrane suitable for removing heavy metals from water, including groundwater.

Abstract: Elastic microfiltration membranes are provided. These membranes may be used in a membrane bioreactor. Due to the elastic nature of the membranes, removal of fouling materials is improved, thereby increasing the efficiency and longevity of the membranes. Methods for forming such membranes and uses of the membranes are also provided, including their use in membrane bioreactors.

Abstract: Membranes are provided for filtering a gas, in some cases air. Membranes using a highly porous cellulose nano fibrous barrier layer with a highly porous (surface-charged) substrate can exhibit high flux, high retention, and low pressure drop in air filtration of toxic aromatic gases, fumes, bacteria, viruses, dusts, and particulate matters.

Abstract: Membranes of the present disclosure possess very thin barrier layers, with high selectivity, high throughput, low fouling, and are long lasting. The membranes include graphene and/or graphene oxide barrier layers on a nanofibrous supporting scaffold. Methods for forming these membranes, as well as uses thereof, are also provided. In embodiments, an article of the present disclosure includes a nanofibrous scaffold; at least a first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof on at least a portion of a surface of the nanofibrous scaffold; an additive such as crosslinking agents and/or particles on an outer surface of the at least first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof.

Abstract: Nanoparticle-fibrous membrane composites are provided as tunable interfacial scaffolds for flexible chemical sensors and biosensors by assembling gold nanoparticles (Au NPs) in a fibrous membrane. The gold nanoparticles are functionalized with organic, polymeric and/or biological molecules. The fibrous membranes may include different filter papers, with one example featuring a multilayered fibrous membrane consisting of a cellulose nanofiber (CN) top layer, an electrospun polyacrylonitrile (PAN) nanofibrous midlayer (or alternate material), and a nonwoven polyethylene terephthalate (PET) fibrous support layer, with the nanoparticles provided on the fibrous membranes through interparticle molecular/polymeric linkages and nanoparticle-nanofibrous interactions. Molecular linkers may be employed to tune hydrogen bonding and electrostatic and/or hydrophobic/hydrophilic interactions to provide sensor specificity to gases or liquids. The sensors act as chemiresistor-type sensors.

Abstract: Membranes of the present disclosure possess very thin barrier layers, with high selectivity, high throughput, low fouling, and are long lasting. The membranes include graphene and/or graphene oxide barrier layers on a nanofibrous supporting scaffold. Methods for forming these membranes, as well as uses thereof, are also provided. In embodiments, an article of the present disclosure includes a nanofibrous scaffold; at least a first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof on at least a portion of a surface of the nanofibrous scaffold; an additive such as crosslinking agents and/or particles on an outer surface of the at least first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof.

Abstract: Membranes of the present disclosure possess very thin barrier layers, with high selectivity, high throughput, low fouling, and are long lasting. The membranes include graphene and/or graphene oxide barrier layers on a nanofibrous supporting scaffold. Methods for forming these membranes, as well as uses thereof, are also provided. In embodiments, an article of the present disclosure includes a nanofibrous scaffold; at least a first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof on at least a portion of a surface of the nanofibrous scaffold; an additive such as crosslinking agents and/or particles on an outer surface of the at least first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof.

Abstract: A high flux and low pressure drop microfiltration (MF) membrane and a method for making the MF membrane. The microfiltration membranes are formed by a method that includes: preparing a nanofibrous structure; and modifying the surface of the nanofibrous structure with a surface modifier. The nanofibrous structure includes an electrospun nanofibrous scaffold or a polysaccharide nanofiber infused nanoscaffold or mixtures thereof. The electrospun nanofibrous scaffold can include polyacrylonitrile (PAN) or polyethersulfone (PES))/polyethylene terephthalate (PET) or mixtures thereof. The surface modifier includes polyethylenimine (PEI) and polyvinyl amine (Lupamin) cross-linked by ethylene glycol diglycidyl ether (EGdGE)/glycidyltrimethylammonium chloride (GTMACl) or poly(1-(1-vinylimidazolium)ethyl-3-vinylimdazolium dibromide (VEVIMIBr).

Abstract: The present disclosure provides methods for producing carboxylated nanocelluloses. Compared with conventional methods, the methods of the present disclosure are simple and cost-effective in the production of carboxylated (or carboxy) nanocelluloses, in embodiments nanofibers and/or nanowhiskers, directly from raw biomass, including lignocellulose wood, non-wood sources, non-lignocellulose wood, lignocellulose or pure cellulose. The carboxy groups on the surface of nanocellulose thus produced can then be easily modified into functional derivatives such as amide, acetate, ether, ester, etc. The resulting nanocelluloses may be used to form purifying agents and/or filters to remove impurities from wastewater.