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

Described are porous polymeric membranes that include two opposing sides and that have a variable pore structure through a thickness of the membrane; filter components and filters that include this type of porous polymeric membrane; methods of making the membranes, filter components, and filters; and methods of using the polymeric filter membrane, filter component, or filter.

Providing new distilling and/or de-scaling methods and systems herein is a matter of allowing for thermal balance without the need to fill a hot wet emulsion separation system with more steam and heat rejection devices to waste steam. A solutions set begins with efficiently utilizing three types of waste: (1) de-oiled and/or cooled down produced water; (2) blowdown steam from drum-type boilers (DBs); and (3) return condensate of dry steam from the DBs. It ends with: (1) removing calcium hardness, magnesium hardness and silica, thereby recovering them as useful minerals; and (2) producing distillate for viscous oil recovery by steam injection and de-scaled hot brine for improved oil recovery by hot water flooding and/or other related methods. The vehicle to attain this solutions' set is a multi-effect distillation train comprises a backward feed section along with two flashing stages.

Providing new distilling and/or de-scaling methods and systems herein is a matter of allowing for thermal balance without the need to fill a hot wet emulsion separation system with more steam and heat rejection devices to waste steam. One embodiment begins with efficiently utilizing three types of waste: (1) hot produced water along with its inherited thermal energy; (2) blowdown steam from drum-type boilers (DBs); and (3) return condensate of dry steam from the DBs. It ends with: (1) removing calcium hardness, magnesium hardness and silica, thereby recovering them as useful minerals; and (2) producing distillate for viscous oil recovery by steam injection and de-scaled hot brine for improved oil recovery by hot water flooding and/or other related methods. The vehicle to attain this set of solutions is a recycle brine multi-effect distillation (RB-ME) train comprises a forward feed section and a backward feed section along with two flashing stages.

Disclosed herein are membranes having a first surface, a second surface opposing the first surface, a skin at the first surface having visible pores when viewed at a magnification of 10,000 and a pore size gradient, wherein pore size increases from the second surface to the skin.

A porous membrane has a thickness of 150 m or greater. The pore diameters of a first surface are smaller than the pore diameters of a second surface. The average value of the pore diameters of the first surface is 60 nm or less, and the coefficient of variation of the pore diameters is 10% or greater and 50% or less.

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.

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.

Providing a membrane-forming solution suitable for producing a separation membrane such as a hollow fiber membrane and a flat membrane. A membrane-forming solution including triacetylcellulose having an acetyl group substitution degree of 2.7 or higher, a good solvent for thermally induced phase separation and a poor solvent for thermally induced phase separation, wherein the good solvent is capable of heat-dissolving the triacetylcellulose (at a solid content concentration of 25 mass %), and the poor solvent is incapable of dissolving the triacetylcellulose up to the heat dissolution temperature of the good solvent, wherein both the good solvent and the poor solvent are included so as to enable phase separation of the heat-dissolved triacetylcellulose solution while the heat-dissolved triacetylcellulose solution is cooled to room temperature (from 20 to 30 C.), and wherein a mixing ratio in a total amount of the good solvent and the poor solvent is from 5 to 40 mass % of the good solvent and from 60 to 95 mass % of the poor solvent.

The present invention relates to a composite semipermeable membrane comprising a substrate, a support layer, and a separation function layer, wherein: the support layer includes particles and a thermoplastic resin having a porous structure; the particles are present in the thermoplastic resin and contain at least one material selected from the group consisting of a diene polymer, an acrylic polymer, and an ethylenic polymer; and in a cross section of the support layer, taken in the laser thickness direction, 6 or more of the particles are present in an area which is 3 m from the surface of the support layer in the layer thickness direction and 3 m in the direction along which such surface extends.