Disclosed herein are ceramic selective membranes and methods of forming the ceramic selective membranes by forming a selective silica ceramic on a porous membrane substrate. Representative ceramic selective membranes include ion-conductive membranes (e.g., proton-conducting membranes) and gas selective membranes. Representative uses for the membranes include incorporation into fuel cells and redox flow batteries (RFB) as ion-conducting membranes.

Disclosed herein are ceramic selective membranes and methods of forming the ceramic selective membranes by forming a selective silica ceramic on a porous membrane substrate. Representative ceramic selective membranes include ion-conductive membranes (e.g., proton-conducting membranes) and gas selective membranes. Representative uses for the membranes include incorporation into fuel cells and redox flow batteries (RFB) as ion-conducting membranes.

A method for making a graphene oxide membrane and a resulting free-standing graphene oxide membrane that provides desired qualities of water permeability and selectivity at larger sizes, thinner cross sections, and with increased ruggedness as compared to existing membranes and processes.

Nanoporous selective sol-gel ceramic membranes, selective-membrane structures, and related methods are described. Representative ceramic selective membranes include ion-conductive membranes (e.g., proton-conducting membranes) and gas selective membranes. Representative uses for the membranes include incorporation into fuel cells and redox flow batteries (RFB) as ion-conducting membranes.

A nanocomposite membrane including an -Al.sub.2O.sub.3 membrane support, a -Al.sub.2O.sub.3 intermediate layer that is 300-1200 nm thick and coats a surface of the membrane support, and a nanocomposite layer including SiO.sub.2 and Y.sub.2O.sub.3 that is 25-150 nm thick and coats a surface of the intermediate layer, wherein the nanocomposite layer is porous with an average largest radius micropore of 0.2-0.6 nm. A method of manufacturing the nanocomposite membrane, whereby the membrane support is coated with the -Al.sub.2O.sub.3, a silica source is hydrolyzed with a mixture of water, an alcohol solvent, and a Y source with a sol-gel technique to yield a Si/Y sol-gel, the membrane support is dip coated with the Si/Y sol-gel, and the nanocomposite membrane is calcined. A method of separating a mixture of gas, whereby the mixture of gas is introduced into a permeance cell and fed through the nanocomposite membrane.

A nanocomposite membrane including -Al.sub.2O.sub.3 membrane support, a -Al.sub.2O.sub.3 intermediate layer that is 300-1200 nm thick and coats a surface of the membrane support, and a nanocomposite layer including SiO.sub.2 and Y.sub.2O.sub.3 that is 25-150 nm thick and coats a surface of the intermediate layer, wherein the nanocomposite layer is porous with an average largest radius micropore of 0.2-0.6 nm. A method of manufacturing the nanocomposite membrane, whereby the membrane support is coated with the -Al.sub.2O.sub.3, a silica source is hydrolyzed with a mixture of water, an alcohol solvent, and a Y source with a sol-gel technique yield a Si/Y sol-gel, the membrane support is dip coated with the Si/Y sol-gel, and the nanocomposite membrane is calcined. A method of separating a mixture of gas, whereby the mixture of gas is introduced into a permeance cell and fed through the nanocomposite membrane.

A nanocomposite membrane including an -Al.sub.2O.sub.3 membrane support, a -Al.sub.2O.sub.3 intermediate layer that is 300-1200 nm thick and coats a surface of the membrane support, and a nanocomposite layer including SiO.sub.2 and Y.sub.2O.sub.3 that is 25-150 nm thick and coats a surface of the intermediate layer, wherein the nanocomposite layer is porous with an average largest radius micropore of 0.2-0.6 nm. A method of manufacturing the nanocomposite membrane, whereby the membrane support is coated with the -Al.sub.2O.sub.3, a silica source is hydrolyzed with a mixture of water, an alcohol solvent, and a Y source with a sol-gel technique to yield a Si/Y sol-gel, the membrane support is dip coated with the Si/Y sol-gel, and the nanocomposite membrane is calcined. A method of separating a mixture of gas, whereby the mixture of gas is introduced into a permeance cell and fed through the nanocomposite membrane.

The present invention provides a method for making a porous silica aerogel composite membrane. The porous silicon oxide aerogel composite membrane includes a porous aluminum oxide membrane having a plurality of macro pores with an average diameter larger than 50 nm and a porous silica aerogel membrane formed on at least one side of the porous aluminum oxide membrane and the macro pores of surface layers of the porous aluminum oxide membrane where the porous silica aerogel membrane has a plurality of meso pores with an average diameter of 250 nm and is derived from methyltrimethoxysilane precursor by a sol-gel synthetic method.

A nanocomposite membrane including an -Al.sub.2O.sub.3 membrane support, a -Al.sub.2O.sub.3 intermediate layer that is 300-1200 nm thick and coats a surface of the membrane support, and a nanocomposite layer including SiO.sub.2 and Y.sub.2O.sub.3 that is 25-150 nm thick and coats a surface of the intermediate layer, wherein the nanocomposite layer is porous with an average largest radius micropore of 0.2-0.6 nm. A method of manufacturing the nanocomposite membrane, whereby the membrane support is coated with the -Al.sub.2O.sub.3, a silica source is hydrolyzed with a mixture of water, an alcohol solvent, and a Y source with a sol-gel technique to yield a Si/Y sol-gel, the membrane support is dip coated with the Si/Y sol-gel, and the nanocomposite membrane is calcined. A method of separating a mixture of gas, whereby the mixture of gas is introduced into a permeance cell and fed through the nanocomposite membrane.

A hydrophobic porous silica aerogel composite membrane for a vacuum membrane distillation device and a vacuum distillation method are disclosed. The vacuum membrane distillation device has a case and the hydrophobic porous silica aerogel composite membrane accommodated in the case to divide a chamber defined by the case into a feed part configured to feed a first fluid containing water molecules and a permeate part configured to collect a second fluid containing the water molecules. The hydrophobic porous silica aerogel composite membrane includes a porous aluminum oxide membrane that has a plurality of first pores with average pore diameter larger than 50 nm and a porous silica aerogel membrane that has a plurality of second pores of 2 to 50 nm and is formed on at least one side of the porous aluminum oxide membrane facing the feed part by methylmethoxysilane as a precursor and a sol-gel synthetic process.