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

A polyimide separation membrane is comprised of a polyimide, a halogen compound (e.g., halogenated aromatic epoxide) that is soluble in the polyimide and a hydrocarbon having 2 to 5 carbons (e.g., ethane, ethylene, propane or propylene). The gas separation membrane has improved selectivity for small gas molecules such as hydrogen compared to polyimide membrane not containing the halogen compound or hydrocarbon. The polyimide separation membrane may be made by shaping a dope solution comprised of a polyimide, a halogen containing compound that is soluble in the polyimide, removing the solvent and then exposing the untreated polyimide membrane to a treating atmosphere comprising a hydrocarbon having 2 to 5 carbons for a sufficient time to form the polyimide membrane.

The present invention relates to polymer compositions (C) for the preparation of porous article, notably microporous membranes or hollow fibers. More particularly, the present invention relates to a process of preparing a porous article from a blend of at least one semi-crystalline or amorphous polymer (P) with an additive followed by a step of shaping the article and contacting the article with water to dissolve the additive and create an interconnected pore network within the shaped article.

A hollow fibre membrane having a coiled, a hemihelix, a helical or an undulated native form, in which the membrane can be stretched by up to 4-times its original length with no plastic deformation, and wherein the native form of the membrane is produced by the asymmetric flow of liquid polymer through an opening of a die or nozzle.

Disclosed herein is a double-layer ion-selective membrane, method of production, applications of the double-layer ion-selective membrane as a redox flow cell, a fuel cell, and used for wastewater and air purification. The double-layer ion-selective membrane is comprised of a polyetherimide (PEI) layer and an ultrathin layer comprising porous boron nitride (PBN) flakes enmeshed by a NAFION? resin. The double layer membrane exhibits ion-selectivity and ion-conductivity enabling the membrane to be used in a redox flow cell battery, a fuel cell battery, and to be used in wastewater and air purification applications.

Disclosed is a thin film composite hollow fiber that includes an outer support layer having a thickness of 10 to 1000 m and a polyamide thin film layer having a thickness of 1 to 10000 nm; and has a transmembrane pressure resistance rate of higher than 15 bar and a pure water permeability rate of higher than 0.8 Lm.sup.2h.sup.1bar.sup.1. Also disclosed are methods of preparing the above-described support and composite hollow fiber.

The present invention relates to a composite porous hollow-fiber membrane including a first layer and a second layer which each include a fluororesin-based polymer, in which the first layer has a columnar texture oriented in a longitudinal direction of the composite porous hollow-fiber membrane, the columnar texture has an average value v of a Raman orientation parameter calculated with the specific formula, and the second layer has a three-dimensional network texture and has an average surface-pore diameter of 5.0 nm to 5.0 m.

Described herein are mixed matrix filtration membranes and related, dendrimers, dendrimer particles, compositions, methods and systems and in particular mixed matrix filtration membranes with an embedded dendrimer particles and related compositions, methods, and systems wherein each dendrimer particle comprises at least two dendrimers each having at least two core chemical moieties having a core multiplicity Nc; branch cell units attached to the core chemical moiety or one to another, with the branch cell units attached one to another having a branch cells multiplicity Nb; and a number of surface functional groups Z presented on terminal branch cell units, wherein Z=NcNb.sup.G with G?3.

A method for forming an isoporous graded film comprising multiblock copolymers and isoporous graded films. The films have a surface layer and a bulk layer. The surface layer can have at least 1?10.sup.14 pores/m.sup.2 and a pore size distribution (d.sub.max/d.sub.min)) of less than 3. The bulk layer has an asymmetric structure. The films can be used in filtration applications.

Assembly for treating fluids, comprising a support (12) having a first and second oppositely arranged surfaces (121) for backing support of a semi permeable membrane (11), a first fluid conveying compartments (124) interposed between the first and second surfaces, a plurality of first fluid passages (126) extending from the first surface (121) and being in fluid communication with the first compartments (124), and a first duct attached to the support (12) and in fluid communication with the first compartments. The assembly comprises a second compartment (125) arranged for conveying fluid and different from the first compartment, and a second duct attached to the support (12) and configured to be in fluid communication with the second compartment (125).