A substrate for a liquid filter contains a polyolefin microporous membrane. A mean flow pore size d.sub.PP in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to gas-liquid phase substitution is from 1 nm to 20 nm. A mean flow pore size d.sub.LLP in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to liquid-liquid phase substitution is from 1 nm to 15 nm. A difference (d.sub.PP?d.sub.LLP) between the mean flow pore size d.sub.PP and the mean flow pore size d.sub.LLP is 12 nm or less, and a thickness of the polyolefin microporous membrane is from 4 to 25 ?m.

A substrate for a composite membrane includes a microporous polyolefin membrane for carrying a hydrophilic resin compound within the pores of the microporous membrane wherein: the average pore diameter is 1 nm to 50 nm; the porosity is 50% to 78%; the membrane thickness is 1 m to 12 m; and, when a mixed solution of ethanol and water (volume ratio 1/2) is dripped onto a surface of the microporous polyolefin membrane which has not undergone hydrophilization treatment, the contact angle 1 between the droplet and the surface is 0 to 90 degrees 1 second after the dripping, and the contact angle 2 between the droplet and the surface is 0 to 70 degrees 10 minutes after the dripping, and the rate of change of the contact angle ((12)/1100) is 10 to 50%.

A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter and using reverse osmosis.

A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter.

A porous membrane has a thickness of 150 m or greater. The pore diameters of a first surface are smaller than the pore diameters of a second surface. The average value of the pore diameters of the first surface is 60 nm or less, and the coefficient of variation of the pore diameters is 10% or greater and 50% or less.

The present invention is a structure, method of making and method of use for a novel macroscopic hierarchically structured, nitrogen-doped, nano-porous carbon membrane (HNDCMs) with asymmetric and hierarchical pore architecture that can be produced on a large-scale approach. The unique HNDCM holds great promise as components in separation and advanced carbon devices because they could offer unconventional fluidic transport phenomena on the nanoscale. Overall, the invention set forth herein covers a hierarchically structured, nitrogen-doped carbon membranes and methods of making and using such a membranes.

Polymer compositions containing polyethylene particles having a multi-modal molecular weight distribution are disclosed. The polymer compositions are well suited to producing porous substrates through a sintering process. Formulations made according to the present disclosure can produce porous substrates having improved flexibility demonstrated by an increased flexural strength while still retaining excellent pressure drop characteristics.

The present invention is a structure, method of making and method of use for a novel macroscopic hierarchically structured, nitrogen-doped, nano-porous carbon membrane (HNDCMs) with asymmetric and hierarchical pore architecture that can be produced on a large-scale approach. The unique HNDCM holds great promise as components in separation and advanced carbon devices because they could offer unconventional fluidic transport phenomena on the nanoscale. Overall, the invention set forth herein covers a hierarchically structured, nitrogen-doped carbon membranes and methods of making and using such a membranes.

A substrate for a liquid filter that contains a polyolefin microporous membrane, in which a mean flow pore size d.sub.pp in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to gas-liquid phase substitution is from 1 nm to 20 nm, a mean flow pore size d.sub.LLP in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to liquid-liquid phase substitution is from 1 nm to 15 nm, a difference (d.sub.pp-d.sub.LLP) between the mean flow pore size d.sub.pp and the mean flow pore size d.sub.LLP is 12 nm or less, and a thickness of the polyolefin microporous membrane is from 4 to 25 ?m.

A gas separation membrane, characterized by having a porous support and a polyamine layer formed on the porous support, the number-average molecular weight of the polyamine constituting a part of the polyamine being 100,000-500,000.