Provided herein are methods for making a freeze-cast material having a internal structure, the methods comprising steps of: determining the internal structure of the material, the internal structure having a plurality of pores, wherein: each of the plurality of pores has directionality; and the step of determining comprises: selecting a temperature gradient and a freezing front velocity to obtain the determined internal structure based on the selected temperature gradient and the selected freezing front velocity; directionally freezing a liquid formulation to form a frozen solid, the step of directionally freezing comprising: controlling the temperature gradient and the freezing front velocity to match the selected temperature gradient and the selected freezing front velocity during directionally freezing; wherein the liquid formulation comprises at least one solvent and at least one dispersed species; and subliming the at least one solvent out of the frozen solid to form the material.

A hollow-fiber membrane according to an aspect of the present disclosure contains a polytetrafluoroethylene or a modified polytetrafluoroethylene as a main component and has an average outer diameter of 1 mm or less and an average inner diameter of 0.5 mm or less. In a measurement of a heat of fusion of the polytetrafluoroethylene or the modified polytetrafluoroethylene with a differential scanning calorimeter, when the polytetrafluoroethylene or modified polytetrafluoroethylene is subjected to a first step of heating from room temperature to 365° C., a second step of cooling from 365° C. to 350° C., maintaining the temperature, subsequently cooling from 350° C. to 330° C., and further cooling from 330° C. to 305° C., and a third step of cooling from 305° C. to 245° C. at a rate of −50° C./min and subsequently heating from 245° C. to 365° C. at a rate of 10° C./min, a heat of fusion from 296° C. to 343° C. in the third step is 30.0 J/g or more and 45.0 J/g or less.

Composite materials for removing hydrophobic components from a fluid include a porous matrix polymer, carbon nanotubes grafted to surfaces of the porous matrix polymer, and polystyrene chains grafted to the carbon nanotubes. Examples of porous matrix polymer include polyurethanes, polyethylenes, and polypropylenes. Membranes of the composite material may be enclosed within a fluid-permeable pouch to form a fluid treatment apparatus, such that by contacting the apparatus with a fluid mixture containing water and a hydrophobic component, the hydrophobic component absorbs selectively into the membrane. The apparatus may be removed from the fluid mixture and reused after the hydrophobic component is expelled from the membrane. The composite material may be prepared by grafting functionalized carbon nanotubes to a porous matrix polymer to form a polymer-nanotube composite, then polymerizing styrene onto the carbon nanotubes of the polymer-nanotube composite.

The present invention relates to a method for producing a porous membrane, the method being characterized in that a solvent system comprising 2-pyrrolidone and N-alkyl-2-pyrrolidone is used, wherein the content ratio of 2-pyrrolidone to N-alkyl-2-pyrrolidone in the solvent system is from 90%:10% to 10%:90%, based on mass %, and wherein N-alkyl-2-pyrrolidone is N-propyl-2-pyrrolidone and/or N-butyl-2-pyrrolidone. Furthermore, the present invention relates to a porous membrane obtainable by said method. Moreover, the present invention relates to the use of a specific solvent system for the production of a porous membrane.

Porous liquid-filtering membranes are provided having a boundary region substantially surrounding the pore region and having greater tear resistance than the pore region.

Provided are a porous film having excellent surface smoothness and a method for producing the same. The surface roughness of a porous film of polyvinylidene fluoride, polyethersulfone, polyimide and/or polyamide-imide is Ra 30,000 Å or less. The opening diameter of the porous film is preferably from 100 nm to 5000 nm. The method for producing a porous film preferably includes a step for kneading a varnish containing fine particles and at least one resin selected from the group consisting of polyvinylidene fluoride, polyether sulfone, polyamic acid, polyimide, polyamide-imide precursor, and polyamide-imide. The varnish preferably has a viscosity at 25° C. of 0.1-3 Pa.Math.s, a solids fraction concentration of 10-50 mass %, and a fine particle average particle size of 10-5000 nm.

There is described a method of preparing solid particles of a compound, said method comprising controlling provision of a liquid phase, wherein said liquid phase comprises a solution of the compound, in a first flow direction to a membrane, said membrane defining a plurality of pores; and controlling the supersaturation of the liquid phase after it has passed through the membrane via the plurality of pores, to form solid particles of the compound. The method may comprise a continuous method.

Embodiments of the present disclosure describe an isoporous polymer membrane comprising a polymeric film having a plurality of isopores, wherein the isoporous polymer membrane is characterized in that it has one or more of the following features: a porosity of about 20% or greater, a plurality of isopores arranged in an ordered array, wherein the plurality of isopores extend from a first membrane surface to a second membrane surface along an axis perpendicular to the first and second membrane surfaces, a membrane size of about 45 cm.sup.2 or greater, and a pore size of about 2 μm or less. Embodiments of the present disclosure also describe methods of fabricating the isoporous polymer membranes, applications using the isoporous polymer membranes, and the like.

A first wafer has a first stop layer deposited on a substrate, the substrate used to form a base support structure. A second wafer has a second stop layer deposited on a sacrificial substrate, and a filter layer deposited on the second stop layer. A rib layer is deposited on one of: the first stop layer of the first layer; or a third stop layer that is deposited over the filter layer. A rib pattern is formed in the rib layer. The first and second wafers are flip bonded such that the rib pattern is joined between the filter layer and the first stop layer. Elongated voids are formed within the filter layer. The base support structure is formed within the substrate of the first wafer such that there is a fluid flow path between the base support structure, the rib layer, and the elongated voids of the filter layer.

The present invention relates to a porous membrane including a plurality of through-type pores, and when the porous membrane is used, a particle to be analyzed and a reactive particle may be reacted one-to-one, thereby increasing the efficiency and accuracy of particle analysis.