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: Membranes comprising first and second microporous surfaces, and, a porous bulk between the surfaces, the bulk comprising first and second regions; the first region comprising a first set of pores having outer rims, and having 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 controlled pore size, and a polymer matrix supporting the first set of pores; the second region comprising a third set of pores having outer rims, and having a controlled pore size, and a fourth set of pores connecting the outer rims of the third set of pores, the fourth set of pores having a controlled pore size, and a polymer matrix supporting the third set of pores; 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: 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 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: Membranes comprising first and second surfaces, the first surface comprising a patterned surface comprising peaks and valleys, first region surfaces comprising peaks, and second region surfaces comprising valleys; a porous bulk between the surfaces, the bulk comprising first region bulks and second region bulks; the region bulks extending from their respective region surfaces, the first region bulks comprising a first set of pores having outer rims, and a second set of pores connecting the outer rims of the first set of pores, and a first polymer matrix supporting the first set of pores; the second region bulks comprising a third set of pores having outer rims, and a fourth set of pores connecting the outer rims of the third set of pores, and a second polymer matrix supporting the third set of pores; filters including the membranes, and methods of making and using the membranes, are disclosed.

Abstract: Disclosed are silica nanoparticles that are suitable as templates for preparing membranes of controlled pore sizes and pore arrangements. The silica nanoparticles have a density of about 1.96 g/cm3 or less. Also disclosed is a method of preparing such nanoparticles which involves reacting an orthosilicate and an alcohol or a mixture of alcohols in an aqueous medium in the presence of a salt of the metal or a metalloid compound, optionally in combination with ammonium hydroxide, isolating the resulting nanoparticles, and treating the resulting particles with an acid.

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: 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: Membranes comprising first and second microporous surfaces, and, a porous bulk between the surfaces, the bulk comprising first and second regions; the first region comprising a first set of pores having outer rims, and having 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 controlled pore size, and a polymer matrix supporting the first set of pores; the second region comprising a third set of pores having outer rims, and having a controlled pore size, and a fourth set of pores connecting the outer rims of the third set of pores, the fourth set of pores having a controlled pore size, and a polymer matrix supporting the third set of pores; and methods of making and using the membranes, are disclosed.

Abstract: Membranes comprising first and second surfaces, the first surface comprising a patterned surface comprising peaks and valleys, first region surfaces comprising peaks, and second region surfaces comprising valleys; a porous bulk between the surfaces, the bulk comprising first region bulks and second region bulks; the region bulks extending from their respective region surfaces, the first region bulks comprising a first set of pores having outer rims, and a second set of pores connecting the outer rims of the first set of pores, and a first polymer matrix supporting the first set of pores; the second region bulks comprising a third set of pores having outer rims, and a fourth set of pores connecting the outer rims of the third set of pores, and a second polymer matrix supporting the third set of pores; filters including the membranes, and methods of making and using the membranes, 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: 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 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 silica nanoparticles that are suitable as templates for preparing membranes of controlled pore sizes and pore arrangements. The silica nanoparticles have a density of about 1.96 g/cm3 or less. Also disclosed is a method of preparing such nanoparticles which involves reacting an orthosilicate and an alcohol or a mixture of alcohols in an aqueous medium in the presence of a salt of the metal or a metalloid compound, optionally in combination with ammonium hydroxide, isolating the resulting nanoparticles, and treating the resulting particles with an acid.

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, filters including the membranes, and methods of making and using the membranes, are disclosed.

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.