Technologies are generally described for a membrane that may incorporate a graphene layer perforated by a plurality of nanoscale pores. The membrane may also include a gas sorbent that may be configured to contact a surface of the graphene layer. The gas sorbent may be configured to direct at least one gas adsorbed at the gas sorbent into the nanoscale pores. The nanoscale pores may have a diameter that selectively facilitates passage of a first gas compared to a second gas to separate the first gas from a fluid mixture of the two gases. The gas sorbent may increase the surface concentration of the first gas at the graphene layer. Such membranes may exhibit improved properties compared to conventional graphene and polymeric membranes for gas separations, e.g., greater selectivity, greater gas permeation rates, or the like.

A method of making a gas separation membrane by providing a plating vessel with a volume of plating solution of gas-selective metal ions into which is placed a porous support. The plating solution is circulated over a surface of the porous support while maintaining conditions within the plating vessel so as to promote the electroless deposition. The circulation rate of the plating solution is such as to enhance the metal deposition onto the surface of the porous support in the formation of the gas separation membrane.

A composite nanoporous metal membrane, a method of making same, and a method of using same to filter supercritical CO.sub.2 are provided. The method of making generally includes a) providing a sintered coarse porous layer; b) applying to an outer face of the coarse porous layer second metal particles; c) sintering to form a structure comprising coarse and intermediate layers; d) applying a suspension of third metal particles; e) drying the suspension of third particles; f) pressing the dried layer of third particles; and g) sintering to form a composite nanoporous metal membrane. The composite nanoporous metal membrane generally includes: a) a sintered coarse layer; b) an intermediate layer comprising first metal particles and second metal particles joined in a sintered structure which is sintered to the coarse layer; and c) a fine layer comprising third metal particles joined in a sintered structure which is sintered to the intermediate layer.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80 C. for a period of time.

In general, embodiments of the present disclosure describe mixed linker metal-organic framework (MOF) membrane composition, the MOF composition comprises a plurality of polynuclear metal clusters, wherein at least one of the polynuclear metal clusters includes a group IV metal or rare earth metal; and a plurality of polydentate linkers linking one or more polynuclear metal clusters; wherein the MOF has asymmetric pore aperture; wherein the composition is represented by the general formula: M-L1.sub.(100-x)-L2.sub.x including a metal (M) and linkers L1 and L2, wherein x is the molar percentage of L2 in membranes.

A method of preparing a flexible ceramic membrane by combining manganese oxide with layer-by-layer assembly technology, which belongs to the field of drinking water purification and wastewater pollution control, is used to solve the problems of poor hydrophilicity of existing organic membranes and high cost of ceramic membranes prepared using organic membranes. The advantages of the polyelectrolyte layer's anti-chlorination property is utilized to acquire the advantages of flexible ceramics, thereby solving the problems of poor hydrophilicity and high cost of existing organic membranes. The binding force of positive and negative charges is utilized for intercepting colloidal substances in water so as to solve the problem of fouling. Therefore, a foundation for its research in the field of drinking water purification and wastewater pollution control is laid. The method includes (a) pretreatment of organic membrane, (b) preparation of preformed solution, (c) introduction of polar groups, (d) preparation of polycationic coating solution, (e) preparation of coating solution A and B, (f) in-situ layer-by-layer assembly, (g) repetition of (f), and (h) drying and storing in deionized water.

Carbon-doped layers and methods of making and using same. In various examples, a carbon-doped layer is porous. In various examples, a carbon-doped layer is a carbon-doped metal oxide and/or metal layer. In various examples, a carbon-doped layer is disposed on at least a portion of substrate. In various examples, a method of making carbon-doped layer(s) comprises contacting a substrate with liquid carbon precursor(s) and optionally, water, and contacting the substrate with liquid precursor(s) and optionally, water with one or more vapor-phase metal and/or metal oxide precursor(s), where the carbon-doped layer(s) is/are formed. In various examples, a method further comprises the carbon-doped layer(s), where porous carbon-doped layer(s) is/are formed. In various examples, a filtration substrate comprises one or more porous carbon-doped layer(s). In various examples, a filtration substrate is used in a separation method or the like. In various examples, the method is an organic solvent nanofiltration (OSN) or the like.

The present disclosure discloses a preparation method of an organosilica/ceramic composite membrane with a gradient pore structure. The preparation method comprises: (1) selecting a porous ceramic material as a membrane support layer; (2) gradually replacing a solvent with water to prepare zirconium colloidal sols with different particle sizes, and successively coating the prepared zirconium colloidal sols onto a ceramic support from large to small so as to form a membrane transition layer with a gradient pore structure; and (3) catalytically synthesizing an organosilica polymeric sol using hydrochloric acid, coating the prepared organosilica sol onto the preheated transition layer through ultrasonic thermal spraying to undergo heat treatment, so as to prepare the organosilica/ceramic composite membrane with the gradient pore structure. According to the present disclosure, the transition layer with the gradient pore structure is prepared by using the zirconium colloidal sols with different particle sizes. An ultrathin defect-free organosilica separation layer is prepared through ultrasonic thermal spraying. As a result, the obtained organosilica/ceramic composite membrane can be applied to the fields of salt-containing dye wastewater treatment and polypeptide bioactive substance separation.

Provided is a gas separation membrane separates a specific gas component from a mixed gas having a plurality of gas components by allowing the specific gas component to permeate therethrough, the gas separation membrane including: a support layer formed of a porous body having pores; a separation layer provided on one surface of the support layer and having a gas separation ability for the specific gas component; and a blocking portion provided corresponding to a defective portion where the separation layer has a defect and the support layer is exposed, and containing metal.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80 C. for a period of time.