Abstract: The present invention provides, in certain embodiments, a negatively charged microporous membrane comprising a porous substrate and a crosslinked coating having fixed negative charges. The crosslinked coating can be prepared, e.g., from a polymerized composition comprising an unsaturated monomer having an anionic group, an N-(hydroxymethyl)- and/or N-(alkoxymethyl)-acrylamide, a hydrophilic unsaturated monomer, and an initiator. The present invention further provides, in some embodiments, a negatively charged microporous membrane comprising a porous substrate and a crosslinked coating prepared from a polymerized composition comprising an unsaturated monomer having an anionic group, an N-(hydroxymethyl)- or N-(alkoxymethyl)-acrylamide, a polysaccharide, and an initiator. The membranes of the present invention are suitable for use in ion exchange chromatography, for example, in the separation and purification of positively charged species such as proteins.

Abstract: The present invention provides a positively charged microporous membrane having a protein binding capacity about 25 mg/ml or greater comprising a hydrophilic porous substrate and a crosslinked coating that provides a fixed positive charge to the membrane. The present invention further provides a positively charged microporous membrane comprising a porous substrate and a crosslinked coating comprising pendant cationic groups. The membranes of the present invention find use in a variety of applications including ion-exchange chromatography, macromolecular transfer, as well as detection, filtration and purification of biomolecules such as proteins, nucleic acids, endotoxins, and the like.

Abstract: The present invention provides a membrane comprising (a) polymer solids comprising 60 wt. % or more of a fully synthetic organic polymer and optionally about 40 wt. % or less of a polymer of natural origin and (b) a cellulose compound which allows for the detection of a biological molecule of interest, wherein the cellulose compound is uniformly distributed throughout the surface of the membrane. The present invention also provides methods of preparing and using such membranes.

Abstract: Hydrophilic inter-penetrating network charge modified microporous membranes are provided as well as a method of preparing the membranes by casting a membrane matrix blend containing matrix polymer, a solvent system, a wetting polymer compatible with the matrix polymer, and a charge modified system which forms a cross-linked interpenetrating network structure within the microporous membrane substrate during the membrane fabrication process which network structure optionally can be locked in by heat curing. The membranes are useful for filtering ultrapure water with 18 megaohm-cm resistivity for the electronic industry, and they can also be used for the removal of a variety of contaminants from fluid media, such as very fine negatively charged particles, bacteria and endotoxins, with greatly enhanced filtration efficiency.

Abstract: Hydrophilic inter-penetrating network charge modified microporous membranes are provided as well as a method of preparing the membranes by casting a membrane matrix blend containing matrix polymer, a solvent system, a wetting polymer compatible with the matrix polymer, and a charge modified system which forms a cross-linked inter-penetrating network structure within the microporous membrane substrate during the membrane fabrication process which network structure optionally can be locked in by heat curing. The membranes are useful for filtering ultra pure water with 18 megaohm-cm resistivity for the electronic industry, and they can also be used for the removal of a variety of contaminants from fluid media, such as very fine negatively charged particles, bacteria and endotoxins, with greatly enhanced filtration efficiency.

Abstract: A microporous membrane modified by coating or grafting thereon a polyionene material. The thus-modified microporous membrane is useful for separating microorganism-originated contaminants from biological liquids.

Abstract: A modified microporous membrane comprising an organic polymeric microporous membrane having microporous surfaces and having hydroxyl, mercapto, carboxyl, or amino functionality on the surfaces modified by a reactive modifying polymer having a polymer chain and having along the polymer chain epoxy or epithio functional groups capable of reacting with the functionality on the surface of the membrane and terminal neutral chemical functionality. The preferred reactive modifying polymer is made from a free radical polymerization of:(a) a polymerizable compound containing an epoxy or epithio group capable of direct covalent coupling to the surface functionalities of the microporous membrane and a vinyl group capable of free radical polymerization; and(b) ##STR1## wherein R.sub.1 is an alpha, beta ethylenically unsaturated polymerizable radical of two or three carbon atoms;R.sub.2 is an alkyl substituent of two to five carbon atoms having a terminal hydroxyl functionality or (R.sub.3 O).sub.n H,wherein R.sub.

Abstract: Polyionene-transformed modified polymer-polysaccharide separation matrix and use thereof in removing contaminants of microorganism origin from biological liquids are disclosed.