Embodiments of the present disclosure provide for composite materials, methods of making composite materials, methods of using composite materials, and the like. In particular, the present application relates to hollow fibers and to pressure-retarded osmosis systems comprising said fibers. The hollow fibers have an inside layer and an outside layer, wherein the outside layer covers an outside surface of the inside layer, wherein the inside layer forms a boundary around the lumen, wherein the inside layer includes a bi-layer structure, wherein the bi-layer structure includes a sponge-like layer and a finger-like layer, wherein the sponge-like layer is disposed closer to the lumen of the hollow fiber and the finger-like layer is disposed on the sponge-like layer on the side opposite the lumen, wherein the outside layer includes a polyamide layer.

Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m.sup.2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)?Z strength (in MPa) of 50 MPa.sup.2 or greater, preferably 100 MPa.sup.2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300? C. with air flow of less than 500 Gurley seconds.

The process can be used in any hydrocarbon process in which it is desirable to recover hydrogen. The process can include catalytically reforming a hydrocarbon feed, a paraffin dehydrogenation to produce light olefins or a synthesis gas generating process. There is an effluent stream having hydrogen and hydrocarbons that is first sent to an adsorption zone to produce a pure hydrogen stream and a tail gas stream. The tail gas stream is then sent across a feed side of a membrane having the feed side and a permeate side. The membrane that is selected is selective for hydrogen over one or more C1-C6 hydrocarbons and light ends including CO, CO2, N2 and O2, and withdrawing from the permeate side a permeate stream enriched in hydrogen compared with a residue stream withdrawn from the feed side. The permeate stream is then recycled to be sent through the adsorption zone.

A gas separation module comprising: (a) a permeate collection tube; (b) a membrane envelope wound spirally around the tube to provide a wound membrane structure comprising two end faces; and (c) an anti-telescoping device (ATD) secured to the permeate collection tube, the ATD comprising: (i) an inner peripheral part, (ii) an outer peripheral part which surrounds the inner peripheral part, (iii) one or more connection parts which connect the inner peripheral part and the outer peripheral part and which contacts with one of said end faces; (iv) vents which allow gas to flow through the ATD; wherein the ATD satisfies Formula (1): (L CP?L contact)/(L VENT)=R Formula (1) wherein: R is from 1.47 to 1.88; L VENT is the cross sectional area of the vents which allow gas to flow through the ATD; L CP is the total area inside the outer peripheral part; and L contact is the contact area of the connection parts and the end face of the wound membrane envelope. Clamps are also claimed.

Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m.sup.2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)Z strength (in MPa) of 50 MPa.sup.2 or greater, preferably 100 MPa.sup.2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300 C. with air flow of less than 500 Gurley seconds.

Provided is a method of manufacturing a multilayer mixed matrix membrane which includes providing a support layer, casting a hydrophilic layer on a surface of the support layer, casting a hydrophobic layer on the hydrophilic layer, and allowing the layers to form a multilayer mixed matrix membrane. Also provided is a method of manufacturing a hollow fiber composite matrix membrane which includes providing a first solution having a hydrophilic polymer, providing a second solution having a hydrophobic polymer, and extruding the first and second solutions to form a multilayer hollow fiber composite matrix membrane. Additionally, a plate-and-frame membrane module for direct contact membrane distillation using a multilayer mixed matrix membrane is provided. The plate-and-frame membrane module includes a feed inlet capable of distributing process solution throughout the membrane module, a permeate inlet capable of distributing process solution throughout the membrane module, a tortuous promoter comprising multiple flow channels, a feed outlet, and a permeate outlet.

A polymer of intrinsic microporosity having a repeating subunit including a spirobisindane imide moiety as illustrated below. ##STR00001##

This invention discloses a membrane composition, a method of making, and applications for a new type of high selectivity, high plasticization-resistant and solvent-resistant, both chemically and UV cross-linked polyimide membranes. Gas permeation tests on these membranes demonstrated that they not only showed high selectivities, but also showed extremely high CO.sub.2 plasticization resistance under CO.sub.2 pressure up to 4923 kPa (700 psig). This new type of high selectivity, high plasticization-resistant and solvent-resistant, both chemically and UV cross-linked polyimide membranes can be used for a wide range of gas separations such as separations of H.sub.2/CH.sub.4, He/CH.sub.4, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, olefin/paraffin separations (e.g. propylene/propane separation), O.sub.2/N.sub.2, iso/normal paraffins, polar molecules such as H.sub.2O, H.sub.2S, and NH.sub.3 mixtures with CH.sub.4, N.sub.2, H.sub.2, and other light gases separations. The membranes can also be used for liquid separations such as in the removal of organic compounds from water.

The present invention relates to a polyetherimide composite nanofiltration membrane and a preparation method thereof, the method comprises the following steps: (1) dissolving polyetherimide and an additive into an organic solvent, stirring and keeping aside for deaeration to prepare a casting solution, blade coating of the casting solution onto a smooth surface of a nonwoven fabric, and placing under an air atmosphere and then putting into deionized water to obtain a support membrane 1, wherein the surface of the nonwoven fabric coated with the casting solution is referred to as surface A; (2) immersing the surface A of the support membrane 1 into an aqueous solution of m-phenylenediamine, taking out and drying in the air, then immersing the surface A into a solution of 1,2,4,5-benzene tetracarbonyl chloride in n-hexane or cyclohexane, and taking out and drying in the air to obtain a support membrane 2; and (3) immersing the surface A of the support membrane 2 into an aqueous solution of EDC.HCl, then adding NHS into the aqueous solution of EDC.HCl, then adding an aqueous solution of ethylene diamine and keeping aside, and then rinsing with deionized water to obtain a polyetherimide composite nanofiltration membrane. The method of the invention has the advantages of low cost, low energy consumption and low pollution; and also has high rejection towards low-molecular-weight compound, stable performance and a longer lifetime.

Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m.sup.2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)?Z strength (in MPa) of 50 MPa.sup.2 or greater, preferably 100 MPa.sup.2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300? C. with air flow of less than 500 Gurley seconds.