Provided are certain polyolefinic membranes which are useful as components of filters for liquid purification. Advantageously, the filter membranes of the disclosure possess greatly reduced concentrations of certain trace metals, thus making them particularly useful in the filtration of liquids used in the fabrication of microelectronic devices. In one aspect, the disclosure provides a filter membrane comprising a polyolefin, wherein said polyolefin has less than about 4 ppm total of metals chosen from titanium, aluminum, iron, zinc, and magnesium.

A method of preparing a membrane comprising the steps of: a) mixing together a membrane-forming polymer, a water-soluble polyetheramine, and a solvent, said mixture containing no component which will react chemically with the polyetheramine; and b) casting said mixture to form the polymer into a solid membrane.

In at least one embodiment, a microporous membrane having a moderate to high water vapor permeability and high liquid water penetration resistance is disclosed. The microporous membrane may be used in building applications, including as or as part of a building wrap, a rain screen, a roofing underlayment, a flashing, a sound proofing material, or an insulation material. The microporous membrane may include at least one thermoplastic polymer, at least one filler, and at least one processing oil. The microporous membrane may be flat or may have ribs. The microporous membrane may include at least one scrim component. A method for forming the microporous membrane is also disclosed.

Disclosed are methods and apparatuses for separating a wax product from a hydrocarbon feedstream by a) conducting a hydrocarbon feedstream to a membrane separation zone; b) retrieving at least one retentate product stream from the first side of the membrane element; c) retrieving at least one permeate product stream having a wax phase and an oil phase from a second side of the membrane element, wherein a pour point of the wax phase of the permeate product stream is higher than a pour point of the oil phase of permeate product stream; and d) separating a wax product from the wax phase of the permeate product stream.

In the method for decolorizing a vegetable wax, a vegetable wax raw material dissolved in an organic solvent is contacted under pressure with a nanofiltration membrane having a higher rejection for a pigment, contained in the vegetable wax raw material, than for the wax components, providing a permeate containing decolorized wax and enriching the pigment in the retentate.

Water-filtration compositions, membranes, devices, and manufacturing processes including graphene oxide with hydrophilic functional groups. Disclosed are a composition comprising graphene oxide with an average particle diameter of no more than about 1 μm and has an oxygen atomic percentage of at least about 30%, a membrane comprising the composition, a water-permeable device comprising the membrane, a method of making the membrane using the composition, and several methods of generating the composition.

An asymmetric hollow fiber (CMS) carbon molecular sieve is made by providing a dope solution comprised of a polvimide and a solvent, at a temperature greater than 250° C. that is less than the storage modulus at a temperature of 250° C., but no more than ten times less as measured using dynamic mechanical thermal analysis from 250° C. to a temperature where the polyimide carbonizes. The polvimide is shaped into a hollow polvimide fiber, the solvent removed and the polyimide hollow fiber is heated to pyroiyze the polvimide and form the asymmetric hollow carbon molecular sieve. The asymmetric hollow fiber carbon molecular sieve has a wall that is defined by an inner surface and outer surface of said fiber and the wall has an inner porous support region extending from the inner surface to an outer raicroporous separation region that extends from the inner porous support region to the outer surface. Surprisingly, when the polyimide has the particular storage modulus characteristics, the method allows for the hollow fiber CMS to be made without any pre-treatmenis or additives to inhibit stractural collapse of the inner microporous region.

Methods of producing an ion exchange membrane support are disclosed. The methods include saturating a polymeric microporous substrate with a charged monomer solution comprising at least one functional monomer, a cross-linking agent, and an effective amount of at least one photopolymerization initiator and polymerizing the at least one functional monomer by exposing the saturated polymeric microporous substrate to ultraviolet light under conditions effective to cross-link the at least one functional monomer and produce the ion exchange membrane support. Methods of producing a monovalent selective ion exchange membrane are also disclosed. The methods include functionalizing an exterior surface of the ion exchange membrane support with a charged compound layer, drying the ion exchange membrane support and soaking the ion exchange membrane support in a solution comprising an acid or a base for an amount of time effective to produce the monovalent selective ion exchange membrane.

A coated ultrafiltration device comprises an upper chamber; a lower chamber; a filtration chamber disposed between the upper chamber and lower chamber; and a semipermeable membrane disposed substantially vertically around the filtration chamber. The semipermeable membrane comprises a coating on a portion of the semipermeable membrane exposed to the filtration chamber, wherein the coating comprises an ultra-low attachment coating that is not derived from animal sources.

An object of the present invention is to provide a nanofiltration membrane having a molecular weight cut-off of 200 to 1,000 and a high amount pf permeate for methanol, and suitable for use as an organic solvent nanofiltration membrane. A nanofiltration membrane formed using a polyamide resin, the nanofiltration membrane having a molecular weight cut-off of 200 to 1,000 and a methanol permeability of 0.03 L/(m.sup.2.Math.bar.Math.h) or more.