Abstract: A method for removing silica from ultra pure water (UPW) comprises passing UPW through a filter comprising a microporous cationically charged membrane having an upstream surface and a downstream surface; and a porous asymmetric membrane having a first surface and an upstream portion and a downstream portion and a second surface, and a bulk between the first surface and the second surface including the upstream portion and the downstream portion, the porous asymmetric membrane having decreasing pore sizes in a direction from the first surface and the upstream portion to the downstream portion and the second surface, the second surface comprising a skin having a nanoporous average pore size, wherein the first surface of the porous asymmetric membrane contacts the downstream surface of the microporous cationically charged membrane; the method including passing the UPW through the microporous cationically charged membrane before passing the UPW through the porous asymmetric membrane.

Abstract: Filters and filter devices for removing silica from ultra pure water, and methods for using the filters and filter devices, are disclosed.

Abstract: Disclosed are hydrophilic porous PTFE membranes comprising PTFE and an amphiphilic copolymer of the formula (I): wherein Rf, Rh1, Rh2, Y, m, n, and o are as described herein. Also disclosed are a method of preparing hydrophilic porous PTFE membranes and a method of filtering fluids through such membranes.

Abstract: Dendrimer conjugates for determining membrane retention level and/or pore structure, methods of determining membrane level/pore structure, and kits including dendrimer conjugates are disclosed.

Abstract: Microporous membranes comprising a single integral layer having first and second microporous surfaces; and, a porous bulk between the microporous surfaces, wherein the bulk comprises at least a first region and a second region; the first region comprising a first set of pores having outer rims, prepared by removing introduced silica dissolvable nanoparticles, the first set of pores having a first controlled pore size, and a second set of pores connecting the outer rims, the second set of pores having a second controlled pore size, and a polymer matrix supporting the first set of pores, wherein the first controlled pore size is greater than the second controlled pore size; the second region comprising a third set of pores prepared by phase inversion, the third set of pores having a third controlled pore size, filters including the membranes, and methods of making and using the membranes, are disclosed.

Abstract: Disclosed is a hollow fiber membrane having hexagonal voids, suitable for use in high throughput filtration applications. Thus, the membrane includes (i) an inner surface; (ii) an outer surface; and (iii) a porous bulk disposed therebetween, wherein the porous bulk comprises at least a first region including: a) a first set of pores having a first controlled pore size and having outer rims; b) a second set of pores connecting the outer rims of the first set of pores, wherein the pore size of the first set of pores is greater than the pore size of the second set of pores; and c) a polymer matrix supporting the first set of pores. Also disclosed is a method for preparing such hollow fiber membranes, which involves coating a filament with a coating composition that includes a membrane-forming polymer and dissolvable nanoparticles, followed by phase invention, and dissolving of the nanoparticles. The filament is removed to obtain the hollow fiber membrane.

Abstract: Disclosed are hydrophilic porous PTFE membranes comprising PTFE and an amphiphilic copolymer, for example, a copolymer of the formula: wherein m and n are as described herein. Also disclosed are a method of preparing hydrophilic porous PTFE membranes and a method of filtering fluids through such membranes.

Abstract: Disclosed are membranes formed from self-assembling diblock copolymers of the formula (I): wherein R1-R4, n, and m are as described herein, which find use in preparing porous membranes. Embodiments of the membranes contain the diblock copolymer self-assembled into a cylindrical morphology. Also disclosed is a method of preparing such membrane which involves spray coating a polymer solution containing the diblock copolymer to obtain a thin film, followed by annealing the thin film in a solvent vapor and/or soaking in a solvent or mixture of solvents to form a nanoporous membrane.

Abstract: Composite membranes comprising a layer having first and second microporous surfaces and a bulk between the surfaces, the bulk comprising a first set of pores having outer rims, and a second set of pores connecting the rims, and a polymer matrix supporting the first set of pores; and, a second layer having first and second porous surfaces and a second bulk between the porous surfaces, wherein the second bulk comprises a fibrous matrix; or, first and second microporous surfaces and a second bulk between the microporous surfaces, the second bulk comprising: a third set of pores having outer rims and a fourth set of pores connecting the rims, and a polymer matrix supporting the third set of pores; a third set of pores prepared by phase inversion; or, a fibrous matrix; or, a third set of pores prepared by stretching, track etching or e-beam, are disclosed.

Abstract: Disclosed are membranes formed from self-assembling block copolymers, for example, a diblock copolymer of the formula (I): wherein R1—R4, n, and m are as described herein, which find use in preparing nanoporous membranes. Embodiments of the membranes contain the block copolymer that self-assembles into a cylindrical morphology. Also disclosed is a method of preparing such membrane which involves spray coating a polymer solution containing the diblock copolymer to obtain a thin film, followed by annealing the thin film in a solvent vapor and/or soaking in a solvent or mixture of solvents to form a nanoporous membrane.

Abstract: Disclosed is a charged hollow fiber membrane having hexagonal voids for use in high throughput applications. The membrane includes: (i) an inner surface; (ii) an outer surface; (iii) a porous bulk disposed therebetween, wherein the porous bulk comprises at least a first region including: a) a first set of pores having a controlled pore size and having outer rims; b) a second set of pores connecting the outer rims of the first set of pores, wherein the pore size of the first set of pores is greater than the pore size of the second set of pores; and c) a polymer matrix supporting the first set of pores; and (iv) at least one charged zone disposed on the inner surface, on the outer surface, and/or in the porous bulk hollow fiber membrane.

Abstract: A porous membrane comprising PTFE blended with PFSA is disclosed.

Abstract: A non-crosslinked PFSA coated porous PTFE membrane is disclosed.

Abstract: Disclosed are hydrophilic porous PTFE membranes comprising PTFE and an amphiphilic copolymer, for example, a copolymer of the formula: wherein m and n are as described herein. Also disclosed are a method of preparing hydrophilic porous PTFE membranes and a method of filtering fluids through such membranes.

Abstract: Methods for hydrophilizing porous PTFE membranes, and hydrophilized membranes, are disclosed.

Abstract: Disclosed are hydrophilic porous PTFE membranes comprising PTFE and an amphiphilic copolymer of the formula (I): wherein Rf, Rh1, Rh2, Y, m, n, and o are as described herein. Also disclosed are a method of preparing hydrophilic porous PTFE membranes and a method of filtering fluids through such membranes.

Abstract: Dendrimer conjugates for determining membrane retention level and/or pore structure, methods of determining membrane level/pore structure, and kits including dendrimer conjugates are disclosed.

Abstract: Composites including porous PTFE membranes comprising an intermediate PTFE membrane having a pore rating of from about 2 nanometers to about 20 nanometers, interposed between, and bound to, porous fluoropolymer membranes having larger pore ratings, and methods of making and using the composites, are disclosed.

Abstract: Membranes comprising a single layer having a first microporous surface; a second microporous surface; and, a porous bulk between the first microporous surface and the second microporous surface, wherein the bulk comprises a first set of pores having outer rims, prepared by removing introduced dissolvable silica nanoparticles, the first set of pores having a first controlled pore size, and a second set of pores connecting the outer rims of the first set of pores, the second set of pores having a second controlled pore size, and a polymer matrix supporting the first set of pores, wherein the first controlled pore size is greater than the second controlled pore size, and wherein the first and/or second microporous surface comprises a neutrally charged, a negatively charged, or a positively charged, surface; filters including the membranes, and methods of making and using the membranes, are disclosed.

Abstract: Porous membranes including a first microporous skin surface having a pore density of at least about 20 pores/50,000 ?m2, and a second porous surface, and a bulk between the surfaces, wherein the bulk has a pore density of at least about 120 pores/mm2, as well as methods of using and methods of making the membranes are disclosed.