The present disclosure is related to porous media with adjustable fluid permeabilities and related systems and methods. In certain cases, the fluid permeability of a porous medium can be adjusted by applying an electrical potential to the porous medium. In some such cases, the application of the electrical potential to the porous medium results in the deposition of material over or the removal of material from the porous medium. Also disclosed herein are systems and methods for capturing species (e.g., acid gases) in which porous media with adjustable fluid permeabilities are used, for example, to control the flow of fluid into and out of a medium used to capture the species.

A separation membrane structure includes a porous support, a first separation membrane and a second separation membrane. The first separation membrane is formed on the porous support and contains high silica zeolite having Si/Al atomic ratio of greater than or equal to 200. The second separation membrane is formed on the first separation membrane and contains cation.

Asymmetric membrane structures are provided that are suitable for various types of separations, such as separations by reverse osmosis. Methods for making an asymmetric membrane structure are also provided. The membrane structure can include at least one polymer layer. Pyrolysis can be used to convert the polymer layer to a porous carbon structure with a higher ratio of carbon to hydrogen.

A filtration filter comprises a metallic mesh having a circumferential shape and radially inner and outer portions. The metallic mesh is adapted to filter out a filtration target object contained in a fluid passing through the membrane. First and second frame members hold the outer portion there between so as to create first and second bent sections separated by a transition section extending between the first and second bent sections. The transition section includes at least one streaked projection.

Asymmetric membrane structures are provided that are suitable for various types of separations, such as separations by reverse osmosis. Methods for making an asymmetric membrane structure are also provided. The membrane structure can include at least one polymer layer. Pyrolysis can be used to convert the polymer layer to a porous carbon structure with a higher ratio of carbon to hydrogen.

Embodiments include a method of making a metal-organic framework membrane comprising contacting a substrate with a solution including a metal ion and contacting the substrate with a solution including an organic ligand, sufficient to form one or more layers of a metal-organic framework on a substrate. Embodiments further include a defect-free metal-organic framework membrane comprising MSiF.sub.6(pyz).sub.2, wherein M is a metal, wherein the thickness of the membrane is less than 1,000 m, and wherein the metal-organic framework has a growth orientation along the [110] plane relative to a substrate.

A filtration filter comprises a metallic mesh having a circumferential shape and radially inner and outer portions. The metallic mesh is adapted to filter out a filtration target object contained in a fluid passing through the membrane. First and second frame members hold the outer portion there between so as to create first and second bent sections separated by a transition section extending between the first and second bent sections. The transition section includes at least one streaked projection.

Described are porous sintered metal membranes that include multiple layers made from different metal particles, that may be useful as filter membranes, and methods of making and using the porous sintered metal membranes.

A cell filtration filter that includes a metal membrane part that has a first main surface on which the cells are to be captured and a second main surface that opposes the first main surface. The metal membrane part has a plurality of hole edges that define a plurality of first through holes and a support region that is arranged around the hole edges and supports the hole edges. In the support region of the metal membrane part, a plurality of second through holes, which have smaller openings than the first through holes, are arranged so as to surround the hole edges. On the first main surface of the membrane part, the hole edges are raised with respect to the support region.

Zeolite membrane sheets for separation of mixtures containing water are provided, as well as methods for making the same. Thin, but robust, zeolite membrane sheets having an inter-grown zeolite crystal film directly on a thin, less than 200 micron thick, porous support sheet free of any surface pores with a size above 10 microns. The zeolite membrane film thickness is less than about 10 microns above the support surface and less than about 5 microns below the support surface. Methods of preparing the membrane are disclosed which include coating of the support sheet surface with a seed coating solution containing the parent zeolite crystals with mean particle sizes from about 0.5 to 2.0 microns at loading of 0.05-0.5 mg/cm2 and subsequent growth of the seeded sheet in a growth reactor loaded with a growth solution over a temperature range of about 45 C. to about 120 C.