This invention allows for the production of high strength and high permeability TIPS membranes using extractable fillers with fine powder PVDF grades.

Methods for making porous polyelectrolyte complex (PEC) films are provided. In an embodiment, such a method comprises coating the surface of a substrate with a polyelectrolyte (PE) coacervate mixture, the PE coacervate mixture comprising a cationic polymer, an anionic polymer, water, and a salt, the PE coacervate having a salt concentration; exposing the coating to an aqueous medium having another salt concentration, for a time to induce solidification of polyelectrolyte complexes (PECs) in the form of a PEC film having pores distributed throughout, wherein a difference Δ?C-M #191 between the salt concentration of the PE coacervate mixture and the salt concentration of the aqueous medium is selected to achieve a predetermined porosity for the porous PEC film.

A process for the preparation of ultrafiltration and microfiltration polymeric flat sheet separation membranes is disclosed, the process comprising a unidirectional cooling step. Membranes prepared according to the process exhibit numerous advantages over ultrafiltration and microfiltration membranes prepared via conventional processes. In particular, the membranes prepared by the present process exhibit remarkable pure water flux, superior mechanical properties and increased anti-fouling characteristics. Also disclosed are particular PVDF ultrafiltration and microfiltration membranes having improved flux, mechanical and anti-fouling properties.

The present invention relates to a thin film composite membrane and a manufacturing method therefor. The thin film composite membrane according to the present invention has superior water flux and excellent salt (NaCl) rejection and/or boron rejection.

Provided is a method including the steps of producing a melt-kneaded product and discharging the melt-kneaded product. In the step of producing a melt-kneaded product, a thermoplastic resin, a non-solvent and an inorganic compound are mixed and melt-kneaded, wherein the non-solvent does not uniformly dissolve the thermoplastic resin of one-quarter mass at a boiling point or 250° C., whichever is lower.

The present invention deals with a method for obtaining membranes in the form of hollow fibers with application in the field of carbon dioxide removal from natural gas. The aforementioned membranes are obtained by means of heat treatment of polymeric membranes. In this method, polymeric membranes are obtained by a phase-inversion technique by immersion-precipitation and are subsequently subjected to a heat treatment, that is, that the membranes effectively become precursor membranes of the heat treatment. The heat treatment process involves the optimization of the heating rate, temperature, and stabilization time variables, aiming at the improvement of the transport properties of the polymeric membranes. After the heat treatment, it becomes possible to use the membranes in separation processes of gases which operate at pressures greater than 30 bar, with selectivity for carbon dioxide (CO.sub.2).

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

Process for making membranes M comprising the following steps: a) providing a dope solution D comprising at least one polymer P and at least one solvent S, b) adding at least one coagulant C to said dope solution D to coagulate said at least one polymer P from said dope solution D to obtain a membrane M, wherein said at least one solvent S comprises more than 50% by weight of at least one compound according to formula (I) (I), wherein R.sup.1 and R.sup.2 are independently C.sub.1 to C.sub.20 alkyl, R.sup.3 is selected from H or an aliphatic rest, 20 R.sup.4 is selected from H or an aliphatic rest, AO represents at least one alkylene oxide, n is a number from 0 to 100. ##STR00001##

A method for producing a gas separation membrane, including the following steps: step (a): treating the surfaces of silica nanoparticles dispersed in a first solvent with a reactive functional group-containing compound, while nanoparticles are being dispersed in the solvent, to thereby prepare a first solvent dispersion of reactive functional group-modified silica nanoparticles; step (b): replacing the first solvent dispersion's dispersion medium of reactive functional group-modified silica nanoparticles prepared in step (a) with a second solvent without drying of dispersion medium, and then reacting functional group-modified silica nanoparticles with dendrimer-forming monomer or hyperbranched polymer-forming monomer in the second solvent's presence so that dendrimer or hyperbranched polymer is added to reactive functional group, to thereby prepare dendrimer- or hyperbranched polymer-bound silica nanoparticles; step (c): mixing dendrimer- or hyperbranched polymer-bound silica nanoparticles prepared in step (b) with a matrix resin; and step (d): applying mixture prepared in step (c) to a substrate, and then removing the solvent.

The invention relates to membranes, membrane modules, and applications therefor. In particular, the invention relates to the construction of membranes for use in osmotically driven membrane processes.