Super-surface selective nanomembranes providing simultaneous high permeation flux and high selectivity

A method comprising selectively separating a substance from a solution, the method comprising

• contacting the solution with a membrane structure comprising:
• a porous support substrate;
• and
• a membrane layer adherently disposed on and in contact with the porous support substrate,
• wherein the membrane layer comprises a nanoporous material having a textured surface,
• wherein the textured surface modified with an organic material.
• wherein the organic material renders the surface superhydrophobic;
• and
• preferentially recovering the substance with high selectivity.

A method of making a membrane structure, the method comprising

• depositing a glass onto a porous support substrate;
• heating the glass and the porous support substrate to a first temperature at a first rate, wherein the first temperature and the first rate are sufficient to cause the glass to separate into a plurality of phases;
• cooling the glass and the porous support substrate to a second temperature at a second rate, wherein the second temperature and the second rate are sufficient to cause the glass to solidify into a mass comprising a plurality of intertwined phases;
• and
• exposing the glass to an etchant to selectively etch one of the pluralities of intertwined phases thereby forming the nanoporous membrane comprising a plurality of mesopores each having a diameter of from 2 to 50 nm.

A method of making a membrane structure, the method comprising:

• depositing a metal layer onto the porous support substrate;
• performing an electrochemical anodization of the metal layer into oxide nanotube arrays to form a layered structure comprising the porous support substrate, the metal layer, and the oxide nanotube arrays;
• chemically etching the layered structure to render the nanotube array permeable by applying an etchant to the porous support substrate;
• and
• functionalizing the anodized surface with an organic polymer/ligand material comprising one selected from the group consisting of a fluorine-terminated silane, a methyl-terminated siloxane.

A method of making a membrane structure, the method comprising:

• forming a sol-gel comprising an oxide;
• applying the sol-gel to a porous support substrate;
• evaporating the sol-gel;
• and
• thermally calcining the membrane structure to form a self-assembled mesoporous silica layer comprising a plurality of nanochannels, wherein the nanochannels are oriented in a direction that is perpendicular to a surface of the porous support substrate.

A method of making a membrane structure, the method comprising:

• preparing a superhydrophobic diatomaceous earth (DE) powder by coating particles with one selected from the group consisting of a plurality of hydrophobic ligand molecules, a surface topography-conforming thin polymer coating, and combinations thereof;
• preparing a powder-polymer hybrid material by combining the plurality of superhydrophobic DE particles with a polymeric binder;
• and
• depositing the powder-polymer hybrid material onto a porous support substrate.