The present invention relates to a chabazite zeolite membrane with a controlled pore size and a production method thereof, wherein the sizes of pore space and pore mouth of the chabazite zeolite membrane are finely controlled through chemical vapor deposition. Through the chemical vapor deposition, defects present in the chabazite zeolite membrane are eliminated, and the pore size is effectively controlled. Thus, unlike hydrophilic membranes showing excellent CO.sub.2/N.sub.2 separation performance under a dry condition, the chabazite zeolite membrane with a controlled pore size according to the present invention has a hydrophobic surface, and thus can maintain excellent CO.sub.2/N.sub.2 separation performance even under a wet condition. Accordingly, the chabazite zeolite membrane of the present invention can effectively capture carbon dioxide from nitrogen under various environmental conditions.

Disclosed herein is filtration material having expanded polytetrafluoroethylene (ePTFE) and method of making. The method comprises expanding polytetrafluoroethylene in a machine direction orienter (MDO) and expanding or stretching to a ratio from about 20:1 up to about 100:1. The sheet of polytetrafluoroethylene is then relaxed. Upon relaxing the sheet of polytetrafluoroethylene, the sheet of polytetrafluoroethylene is fed into a transverse direction orienter (TDO). The temperature of the sheet of polytetrafluoroethylene in TDO is maintained to remain below 200? C. The sheet of polytetrafluoroethylene is then expanded or stretched to a ratio from about 1.5:1 up to about 100:1, with the TDO, thus providing the expanded polytetrafluoroethylene of the present disclosure having increased tensile strength and finer filaments.

An object of the present invention is to provide a separation membrane having high permeability and selective removability of divalent/monovalent ions. The separation membrane of the present invention includes a supporting membrane and a separation functional layer formed on the supporting membrane, in which the separation functional layer contains a polymerized product of a polyfunctional amine with a polyfunctional acid halide, the polyfunctional amine contains a polyfunctional aliphatic amine as a main component, the separation functional layer has a hollow protuberant structure, and the separation functional layer has a relative surface area of 1.1-10.0.

A semi-porous composite membrane and a method of manufacturing the semi-porous composite membrane. The semi-porous composite membrane includes a base supporting substrate comprising ?-Al.sub.2O.sub.3, an outer layer comprising silica, and an intermediate layer comprising crystalline fibers of boehmite, and at least one of a secondary metal oxide and a synthetic polymer, wherein the intermediate layer is disposed between the base supporting substrate and the outer layer. The crystalline fibers of boehmite are a length of 5-150 nm. The semi-porous composite membrane may be employed in membrane reactors.

A pressure-resistant porous macromolecular PMMA filter membrane material comprises the following ingredients in parts by weight: 60-95 parts of PMMA, 60-90 parts of MMA, 0.5-25 parts of surfactant and 5-25 parts of water. The filter membrane material is simple in preparation process, and the prepared pressure-resistant porous macromolecular filter membrane material contains no bubble, has a uniform pore size, an adjustable micro pore size of 0.01-12 ?m, a special-purpose pore size of 13-80 ?m, a porosity of 20-38% and a water permeability rate greater than 20%. The filter membrane material has the characteristics of reusability, light weight, high mechanical strength, excellent impact resistance, high pressure resistance, low molding shrinkage, good water permeability, adjustable pore size and the like.

The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 ?m and includes a portion where a degree of cyclization (I.sub.1600/I.sub.2240) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

Methods are generally provided for forming a membrane. In one embodiment, the method includes: dispersing GO nanoparticles in a solvent; depositing the GO nanoparticles on a support to form a GO membrane; and reducing the GO membrane to form a rGO membrane. Also provided is the rGO membrane formed from such methods, along with a plurality of stacked rGO layers. Methods are also provided for separating water from a water/oil emulsion by, for example, passing water through the rGO membrane.

Methods of preparing reinforced anion exchange membranes are provided, as well as produced membranes and corresponding devices utilizing the membranes. Methods comprise compounding a halide-functionalized polymer (selected to react with amines to yield anion-conducting quaternary amine groups) with thermoplastic polymer(s) (selected to support and/or reinforce the membrane), and with copolymer(s) (selected to enhance the compounding of the polymers)by heating, mixing and coolingto form blend pellets, extruding the blend pellets to form a blend film, cross-linking polymer(s), and functionalizing the blend film to prepare the anion exchange membrane. Functionalization comprises a quaternization step comprising reacting halogen groups of the first polymer with tertiary amines to produce the quaternary amine groups with ion-exchange functionality. Reinforced anion exchange membranes are provided, which are produced by the disclosed methods, functionalized to yield a membrane for fuel cell(s), electrolyzer(s), reversible electrochemical device(s), desalination unit(s), etc.

A composite polyamide reverse osmosis membrane comprising a polyamide layer; where the polyamide layer has a thickness in the range of 50-250 nm, and large open spaces (i.e., free volumes); where the open spaces are defined by a ratio of water flux, J.sub.w, (gfd) divided by the average surface roughness, Ra, (nm) of the polyamide layer; wherein the composite polyamide reverse osmosis membrane has the ratio of J.sub.w/Ra>0.35 gfd/nm when tested at 65 psi, using an aqueous solution containing 250 ppm of NaCl; and a microporous support with a thickness ranging from 100-150 ?m. The present invention also relates to processes of fabricating the composite polyamide reverse osmosis membrane.

A method of manufacturing a hollow fiber carbon membrane, the method includes heating a polymeric precursor to a pyrolysis temperature that is greater than or equal to 900? C. and less than or equal to 1200? C., and pyrolyzing the polymeric precursor at the pyrolysis temperature in a pyrolysis atmosphere that comprises oxygen in an amount that is greater than 0 ppm and less than 200 ppm.