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.

Disclosed are compositions that may be useful for forming synthetic membranes, methods of forming membranes therefrom, and membranes. In an embodiment, a membrane comprises a free hydrophilic polymer and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic diol, and, optionally, a chain extender, wherein the backbone comprises a C.sub.2-C.sub.16 fluoroalkyl or C.sub.2-C.sub.16 fluoroalkyl ether, or the polyurethane comprises an endgroup comprising a C.sub.2-C.sub.16 fluoroalkyl or C.sub.2-C.sub.16 fluoroalkyl ether.

Disclosed are compositions that may be useful for forming synthetic membranes, methods of forming membranes therefrom, and membranes. In an embodiment, a membrane comprises a free hydrophilic polymer comprising a polyoxazoline, and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic 5 diol, and optionally a chain extender.

The present disclosure relates to an electrode system for measuring the concentration of an analyte under in-vivo conditions, comprising an electrode with immobilized enzyme molecules and a diffusion barrier that controls diffusion of the analyte from body fluid surrounding the electrode system to the enzyme molecules.

Disclosed herein are membranes, composition for forming membranes, methods for forming membranes, and sensors and other devices comprising membranes. The membrane comprises a polyurethane component, the polyurethane component comprising a blend of from 5 wt % to 95 wt %, based on the total weight of the polyurethane component, of an amphiphilic polyurethane, and from 5 wt % to 95 wt %, based on the total weight of the polyurethane component, of a hydrophobic polyurethane.

A hydrogen peroxide production method, system, and apparatus is provided for producing large volumes of hydrogen peroxide having concentrations up to and excess of 80% in one continuous cycle. In one aspect, the hydrogen peroxide production system can include an aqueous solution comprised of an NQO1 enzyme, an NQO1 activated compound or molecule, and an NADH or NADPH cofactor for producing hydrogen peroxide, a production chamber having a semi-permeable membrane for receiving the aqueous solution. Here, the membrane can further include one or more molecular weight barriers configured to diffuse the produced hydrogen peroxide there through. The system can also include a collection chamber for receiving the produced hydrogen peroxide, and one or more pumps for circulating the aqueous solution having the hydrogen peroxide to the collection chamber and back to the production chamber.

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.

Polymer membranes include a polymer material that is selectively permeable to acidic gases over methane in a gas stream, such as natural gas. The polymer material may be a polymer membrane comprising a fluorinated polytriazole polymer. The fluorinated polytriazole polymer may further comprise a substituted phenyl or a substituted benzenaminyl. The substituted phenyl or substituted benzenaminyl may be substituted with hydrogen, bromo, fluoro, chloro, iodo, hydroxy, methyl, trifluoromethyl, dimethylamino, tert-butyl, or difluoromethoxy groups. The polymer material may have a degree of polymerization of from 100 to 175. The polymer membranes may be incorporated into systems or methods for removing separable gases, such as acidic gases, from gas streams, such as natural gas.

A filter medium is provided. According to one embodiment of the present invention, the filter medium is implemented by including: a porous second support and a nanofiber web which are sequentially stacked on each of an upper portion and a lower portion of a first support; and a channel through which a filtrate filtered in the nanofiber web flows in a direction of the first support, wherein the first support, the second support, and the nanofiber web satisfy predetermined conditions on a basis weight and a thickness of each layer. In a water treatment operation of the filter medium, the shape, structural deformation, and damage of the filter medium can be minimized, excellent filtration efficiency can be implemented, and a channel can be smoothly secured, thereby securing high flux. In addition, even at high pressure applied during backwashing, the filter medium has an extended use period due to excellent durability of the filter medium. Accordingly, the filter medium can be variously applied in various water treatment fields.

Disclosed is a porous hollow fiber membrane containing a polysulfone-based polymer as a main component, which has an asymmetric structure in which the inner surface side is dense and the outer surface side is coarse, wherein an average of a minor axis diameter of pores of an inner surface is 20 nm or more and 40 nm or less, an open porosity of the inner surface is 10% or more and 30% or less, and a polymer including a monocarboxylic acid vinyl ester unit is supported on at least one of the outer surface and the inner surface. The present invention provides a hollow fiber membrane which has excellent removing performance of substances to be separated such as viruses, and can be used as a separation membrane having high permeability even in a treatment under low pressure.