Described herein is a graphene material based membrane that provides selective resistance for solutes or gas while providing water permeability. A selectively permeable membrane comprising graphene oxide, reduced graphene oxide, and also functionalized or crosslinked between the graphene, that provides enhanced salt separation from water or gas permeability resistance, methods for making such membranes, and methods of using the membranes for dehydrating or removing solutes from water are also described.

An object is to form a hole having a desired size accurately and uniformly in a carbon nanomaterial used for a filter or the like, such as a graphene, a carbon nanotube, or a carbon nanohorn.

Provided is a method for perforating a carbon nanomaterial for forming a hole having a desired size in a carbon nanomaterial, characterized in that the carbon nanomaterial is heated and held at a low temperature in the air containing oxygen of 160 to 250 C. for a predetermined time and that a hole having a desired size is thereby formed uniformly in the carbon nanomaterial by controlling a length of heating time.

Perforated graphene sheets can be used in forming separation membranes. Separation membranes of the present disclosure, which can be used in gas separation processes in some embodiments, can include one or more layers of perforated graphene and one or more layers of another membrane material. Methods for separating a gas mixture can include contacting a gas mixture with the separation membranes, and transiting one or more of the gases through the perforated graphene so as to affect separation.

A membrane for fluid species transport includes a porous substrate and a selective-transport layer comprising 2-D-material flakes. The porous substrate defines surface pores with dimensions larger than 2 microns, and the selective-transport layer coats the porous substrate and spans across the surface pores. The porous substrate can be contacted with a liquid or coating to fill or coat the surface pores of the porous substrate. Next, a 2-D-material-flake solution is deposited on the porous substrate. Evaporation of solvent from the deposited 2-D-material-flake solution forms the selective-transport layer.

A composition of matter including a two-dimensional covalent organic imidazole framework (COF) polymer having an aromatic backbone and ordered nanometer sized pores that may be functionalized with a variety of functional groups. A filtration membrane having both high throughput and highly selective transport or rejection of a species of interest based on size, charge or other molecular properties is readily formed of the two-dimensional COF polymer. The filtration membrane being formed by providing a substrate, such as anodic aluminum oxide (AAO), and then depositing exfoliated carboxyl COF onto the substrate.

A method for making a nanoporous membrane is disclosed. The method provides a composite film comprising an atomically thin material layer and a polymer layer, and then bombarding the composite film with energetic particles to form a plurality of pores through at least the atomically thin material layer. The nanoporous membrane also has a atomically thin material layer with a plurality of apertures therethrough and a polymer film layer adjacent one side of the graphene layer. The polymer film layer has a plurality of enlarged pores therethrough, which are aligned with the plurality of apertures. All of the enlarged pores may be concentrically aligned with all the apertures. In one embodiment the atomically thin material layer is graphene.

The disclosure provides a method for producing a gas separation article, said gas separation article comprising: a gas separation membrane, optionally a support, and optionally an additional support. The disclosure also provides a gas separation membrane obtainable by the aforementioned method as well as use thereof for separation of gases in a gas mixture.

A gas separation membrane comprising the following layers: (ii) a support layer; (ii) a discriminating layer; (iii) a further layer, wherein the further layer comprises groups of Formula (1): M-(O).sub.x wherein: each M independently is a metal or metalloid atom; O is an oxygen atom; and each x independently has a value of at least 4; and (iv) optionally a protective layer; wherein: (a) the support layer (i) and the further layer (iii) are on opposite sides of discriminating layer (ii); and (b) the further layer (iii) comprises 1.5 to 10 atomic % of M of Formula (1) groups, wherein M is as hereinbefore defined.

A gas separation membrane comprising the following layers: (i) optionally a support layer; (ii) a discriminating layer; (iii) a further layer; and (iv) optionally a protective layer; wherein (a) the further layer (iii) and the discriminating layer (ii) each independently comprise groups of Formula (1): M-(O).sub.x wherein: each M independently is a metal or metalloid atom; O is an oxygen atom; and each x independently has a value of at least 4; (b) the further layer (iii) comprises 1.5 to 10 atomic % of M of Formula (1) groups, wherein M is as hereinbefore defined; and (c) the discriminating layer (ii) comprises more than 10 atomic % of M of Formula (1) groups, wherein M is as hereinbefore defined.

A 3D nanopore device for characterizing biopolymer molecules includes a first selecting layer having a first axis of selection. The device also includes a second selecting layer disposed adjacent the first selecting layer and having a second axis of selection orthogonal to the first axis of selection. The device further includes an third electrode layer disposed adjacent the second selecting layer, such that the first selecting layer, the second selecting layer, and the third electrode layer form a stack of layers along a Z axis and define a plurality of nanopore pillars.