Provided are: a porous polyether sulfone film having macrovoids and having excellent dimensional stability; and a production method therefor. Provided is a porous polyether sulfone film having a surface layer (a), a surface layer (b), and a macrovoid layer interposed between the surface layer (a) and the surface layer (b). The macrovoid layer has a partition wall joined to the surface layers (a) and (b) and a plurality of macrovoids surrounded by the partition wall and the surface layers (a) and (b). The surface layer (a) and the surface layer (b) have pores connected to the macrovoids.

The invention relates to macroporous, hydrophobic and isotropic polyvinylidene fluoride (PVDF) membranes having improved properties and to a new method for preparing the same.

The invention is related to a super-hydrophilic/underwater super-oleophobic attapulgite separation membrane, and a preparation method and use thereof. Monodispersed hydrophilic nanoparticulates are loaded on a surface of nanoparticles, to obtain a super-hydrophilic nanocomposite material with a micro-nanostructure. The nanocomposite material is dispersed in a mixed aqueous solution of polyacrylamide and methyl cellulose, to obtain a membrane-forming slurry after vigorous stirring. A disc-shaped porous support is infiltrated with water and placed on a horizontal surface, and then a certain volume of the membrane-forming slurry is slowly and uniformly drip-coated on a surface of the support, dried and sintered to obtain a super-hydrophilic/underwater super-oleophobic microfiltration membrane layer.

Disclosed is a membrane surface modification method. The method is applicable to a variety of hydrophobic membranes by doping selected inorganic particles. One act of the method involves the in-situ embedment of the inorganic particles onto the membrane surface by dispersing the particles in a non-solvent bath for polymer precipitation. Further membrane surface modification can be achieved by hydrothermally growing new inorganic phase on the embedded particles. The embedment of particles is for the subsequent phase growth.

Filter media, filter devices and methods of making filter media are disclosed. The filter media includes a coating on at least a portion of said outer surface. The coating may be polymeric composition having a molecular chain that includes segments of non-polar groups and segments of at least one of polar groups or segments of ionic groups.

Microporous polyamide-imide membranes and methods for making them are disclosed. The microporous membrane includes polyamide-imide polymer, wherein the membrane has an HFE bubble point, and an IPA flow-time. The microporous membrane has an HFE bubble point from about 25 psi to about 200 psi and has an IPA flow-time from about 400 second to about 40,000 seconds. Another microporous polyamide-imide membrane includes a polyamide-imide polymer, wherein the membrane has a HFE bubble point from about 25 psi to about 200 psi. The membrane is asymmetric- and has a tight layer with a thickness of 10 microns. Filter and purification devices incorporating such devices are also disclosed.

Described in the present application are methods of producing silane-crosslinked polymer membranes at moderate temperatures using acid catalysts that, in certain embodiments, result in membranes with unexpectedly high permeabilities and selectivities. In certain embodiments, grafting and crosslinking of the silanes occur by immersing a preformed membrane in a solution comprising a silane and an acid catalyst. Alternatively, in certain embodiments, grafting of silanes to a polymer occurs in the presence of acid catalyst in solution and subsequent casting and drying produces crosslinked membranes. In certain embodiments, an acid catalyst is a weak acid catalyst. Also described in the present application are asymmetric crosslinked polymer membranes with porous layers. In certain embodiments, crosslinked cellulose acetate membranes have permeability up to an order of magnitude greater than the permeability of unmodified cellulose acetate membranes. The membranes have porous layers with a high porosity due to their processing in moderate conditions.

A low cost, high selectivity asymmetric polyimide/polyethersulfone (PES) blend hollow fiber membrane, a method of making the membrane and its use for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, H.sub.2S/CH.sub.4, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. The polyimide/PES blend hollow fiber membrane is fabricated from a blend of a polyimide polymer and PES and showed surprisingly unique gas separation property with higher selectivities than either the polyimide hollow fiber membrane without PES polymer or the PES hollow fiber membrane without PES polymer for gas separations such as for H.sub.2/CH.sub.4, He/CH.sub.4, H.sub.2S/CH.sub.4, CO.sub.2/CH.sub.4 separations.

The present invention relates to a hollow fiber membrane including, sequentially from the center: a first layer having a high-density sponge structure including pores with a size of 1 nm or less; a second layer including a finger-shaped structure; and a third layer having a low-density sponge structure including pores with a size of 10 to 1,000 m, and to a method for producing the hollow fiber membrane.

Embodiments of the present disclosure describe a method of making a membrane comprising contacting one or more membrane materials, a solvent, and a non-solvent at a first temperature sufficient to form a homogenous solution; casting the homogenous solution at about the first temperature; and adjusting the temperature to a second temperature sufficient to induce phase separation of the solvent and non-solvent and form a porous membrane.