Fabricating a zeolite membrane on a substrate includes disposing first zeolite crystals on a substrate to yield a first layer on the substrate and disposing second zeolite crystals on the first layer to yield a second layer on the first layer, thereby yielding a membrane precursor. The membrane precursor is heated at a first temperature for a first length of time, and the temperature of the membrane precursor is increased or decreased from the first temperature to a second temperature. The membrane precursor is heated at the second temperature for a second length of time to yield the zeolite membrane. The second zeolite crystals have a smaller average diameter than the first zeolite crystals. The second temperature can exceed the first temperature or the first temperature can exceed the second temperature.

A hybrid crosslinked polymeric membrane and a process for fabricating the same are provided. Specifically, the hybrid crosslinked polymer membrane comprises a glassy polymer and a ladder-structured polysilsesquioxane and has a crosslinked structure. The hybrid crosslinked polymer membrane can have an excellent permeability of carbon dioxide by virtue of an increase in the free volume and enhanced plasticization resistance, chemical resistance, and durability.

A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).

A membrane modification method for improving liquid membrane separation of carbon dioxide (CO.sub.2) includes grafting an organic substance containing an amine group on a porous membrane material, and loading water into pore channels of the porous membrane material to prepare a supported liquid membrane for a gas mixture separation experiment of CO.sub.2. In the method, the amine group is introduced through chemical grafting to make the water being alkaline when used as membrane liquid. Compared with an alkaline solution as the membrane liquid, the method can avoid the loss of active alkaline substances and increase the permeation flux of CO.sub.2.

A base material for a membrane filter contains 90% by mass or more of aluminum oxide and 0.1% by mass or more and 10% by mass or less of titanium oxide. In a pore distribution curve measured by a mercury porosimeter, the base material has a first peak and a second peak which is higher than the first peak and is located at a pore size larger than that of the first peak, and the volume of pores with a pore size of 7 μm or more is 0.02 cm.sup.3/g or more.

A process for preparing a microcapillary carbon molecular sieve membrane may include extruding a polyvinylidene chloride polymer to a thickness from 10 μm to 1,000 μm to form an extruded polymeric microcapillary film, wherein the extruded polymeric microcapillary film comprises a first end, a second end, and one or more microcapillaries extending from the first end to the second end; pre-treating the extruded polymeric microcapillary film at a temperature from 100° C. to 200° C. for a time from 1 hour to 48 hours to form a pre-treated polymeric microcapillary film; and pyrolizing the pre-treated polymeric microcapillary film at a temperature from 200° C. to 1,500° C. for a time from 15 minutes to 5 hours to form the microcapillary carbon molecular sieve membrane.

A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).

The invention relates to a method for manufacturing a hollow fiber membrane bundle from a plurality of polysulfone and PVP-based hollow fiber membranes which encompasses the providing of a spinning solution comprising a polysulfone-based material, in particular polysulfone, a vinylpyrrolidone-based polymer, in particular polyvinylpyrrolidone, an aprotic solvent, in particular dimethylacetamide, providing a coagulant liquid comprising water and an aprotic solvent, in particular dimethylacetamide, co-extruding the spinning solution and the coagulant liquid through a concentric annular spinneret into a hollow strand, whereby the cavity of the strand is filled with coagulant liquid, conducting the strand through a precipitation gap, introducing the strand into a precipitating bath comprised substantially of water so as to obtain a hollow fiber membrane, conducting the hollow fiber membranes through at least one rinsing bath and drying the hollow fiber membrane obtained, arranging the resulting hollow fiber membranes into a hollow fiber membrane bundle, and treating the hollow fiber membrane bundle with water vapor.

A method for preparing a nanofiltration membrane and a nanofiltration membrane prepared therefrom, the method comprising the following steps: dissolving a polymer in a solvent to prepare a polymer solution, and curing the polymer solution on a support material to form a base membrane; sequentially applying a first liquid-phase solution and a second liquid-phase solution on the base membrane to form a nascent membrane; densifying the nascent membrane by using a solution that contains an alkaline substance; processing the densified nascent membrane by using a solution that contains an acidic substance; and obtaining the nanofiltration membrane after post-processing and drying.

A metal organic framework glass membrane and a preparation method thereof are provided. The preparation method includes a step of heating a crystalline metal organic framework material to the melting temperature at a rate of 1-15° C./min and then naturally cooling the crystalline metal organic framework material. The crystalline metal organic framework material contains a metal node and a ligand A. The metal node is a zinc ion and/or a cobalt ion and the ligand A is imidazole or phosphoric acid. The metal organic framework glass membrane has a wide range of membrane-forming conditions, and the material thereof can be melted without being decomposed within a control range to form a continuous glass layer with good repeatability.