A microporous membrane is made by a dry-stretch process and has substantially round shaped pores and a ratio of machine direction tensile strength to transverse direction tensile strength in the range of 0.5 to 5.0. The method of making the foregoing microporous membrane includes the steps of: extruding a polymer into a nonporous precursor, and biaxially stretching the nonporous precursor, the biaxial stretching including a machine direction stretching and a transverse direction stretching, the transverse direction stretching including a simultaneous controlled machine direction relax.

Microporous polyamide-imide membranes and methods for making them are disclosed. The microporous membrane includes polyamide-imide polymer, wherein the membrane has an HFE bubble point, and an IPA flow-time. The microporous membrane has an HFE bubble point from about 25 psi to about 200 psi and has an IPA flow-time from about 400 second to about 40,000 seconds. Another microporous polyamide-imide membrane includes a polyamide-imide polymer, wherein the membrane has a HFE bubble point from about 25 psi to about 200 psi. The membrane is asymmetric- and has a tight layer with a thickness of 10 microns. Filter and purification devices incorporating such devices are also disclosed.

Hydrophobic flat membrane made from a vinylidene fluoride polymer with a wall, a first surface, and a second surface. The membrane has on its first surface a network structure with open pores and on its second surface a continuous skin in which pores are formed, and adjacent to the skin of the second surface a supporting layer with an isotropic pore structure across the wall thickness, wherein the supporting layer extends over at least 80% of the wall thickness and wherein the pores of the supporting layer have an average diameter of less than 1 m. The weight average of the molecular weight M.sub.W of the vinylidene fluoride polymer lies in the range from 300 000 to 500 000 daltons, and the polydispersivity M.sub.W/M.sub.N is greater than 5.5. The pores in the skin of the second surface have a closed perimeter in the plane of the skin and an average ratio of the extension in the direction of the longest axis thereof to the extension in the direction of the shortest axis thereof of at most 5. The pores in the first surface and second surface have an essentially isotropic distribution of their orientation. The porosity of the membrane lies in the range from 50 to 90 vol. % and the wall thickness in the range from 50 to 300 m. The membrane has a maximum separating pore diameter d.sub.max in the range from 0.05 to 1.5 m.

A filter for filtering nucleated cells that includes a body containing at least either a metal or a metal oxide as its main component; and plural through holes, each of which have a shape other than a square shape, formed therein. An arithmetic average roughness of a first side of the filter part is smaller than a size of a nucleus of the nucleated cells to be filtered.

A filtration membrane, suitably for water filtration, in which the membrane includes a porous substrate layer and an active layer arranged over at least a part of the substrate layer. The active layer has a lamellar structure comprising at least two layers of two-dimensional material. The two-dimensional material comprises transition metal dichalcogenide. There is also provided methods for making the filtration membranes and compositions for use in those methods.

Micro- or nano-pores are produced in a membrane for various applications including filtration and sorting functions. Pores with at least one cross-sectional dimension in or near the nano-scale are provided. Device designs and processing allow for the use of thin film disposition and nano-imprinting or nano-molding to produce arrays of nano-pores in membrane materials functioning in applications such as filtration membranes, drug application/control structures, body fluid sampling structures, and sorting membranes. The nano-imprinting or nano-molding approach is utilized to create nano-elements in an organic or inorganic mold material with at least one nano-element cross-sectional dimension in or close to the nano-scale. These nano-elements can be in various shapes including slits, cones, columns, domes, and hemispheres.

A perfluorocarbon-free membrane composed of a non-perfluorocarbon material having a first side and a second side opposite of the first side. The perfluorocarbon-free membrane also includes a plurality of pores, each having an inlet and outlet and each passing through the non-perfluorocarbon material so that each pore provides fluidic communication between the first and second sides of the non-perfluorocarbon material. A portion of the non-perfluorocarbon material extends over the inlet and outlet of each the plurality of pores so that a cross-sectional area of the inlets and outlets in a direction of the extension of the non-perfluorocarbon material is smaller than a cross-sectional area of the respective pore in the direction of the extension of the non-perfluorocarbon material. The perfluorocarbon-free membrane does not include a hydrophobic perfluorocarbon coating.

Provided are methods, devices, and kits for the isolation and enumeration of one or more components of interest within a liquid sample using microslit filter membranes. This disclosure relates to the enumeration of components within a sample of interest, and more particularly, the capture of such components by efficient isolation using microslit filters with high permeation capacity and precision molecular cut-off characteristics.

A nanoporous polymer membrane with vertically aligned pore channels can be synthesized through self-assembly of amphiphilic block copolymers on a supporting substrate. The pore surface chemistry can be functionalized for selective anion transport,?

Photocurable compositions and methods of preparation and use of such compositions. More particularly, photocurable compositions useful for forming topographical features on surfaces such as membrane surfaces. Methods of forming topographical features on a membrane surface using photocurable compositions.