NOVELTY - The membrane structure comprises a porous support substrate and a membrane layer adherently disposed on and in contact with the porous support substrate. The membrane layer comprises a nanoporous material having a superhydrophobic surface. The superhydrophobic surface comprises a textured surface, and a modifying material disposed on the textured surface. The modifying material comprises an organic material and/or polymeric material. The membrane has a permeation flux of greater than 1000 GPU and a selectivity of hydrophobic molecules to hydrophilic molecules of greater than 50/1.    USE - The membrane structure is useful in an apparatus such as a pervaporation membrane, a fuel cell, a gas separator, a size-exclusive separator, an oil-water separation membrane, a membrane reactor and a catalytic converter, and for selectively separating a substance from a solution (all claimed).    ADVANTAGE - The superhydrophobic membrane structure has high throughput and selectivity, increased permeation flux, and excellent performance thus allowing efficient molecular separation.    DETAILED DESCRIPTION - The membrane structure comprises a porous support substrate and a membrane layer adherently disposed on and in contact with the porous support substrate. The membrane layer comprises a nanoporous material having a superhydrophobic surface. The superhydrophobic surface comprises a textured surface, and a modifying material disposed on the textured surface. The modifying material comprises an organic material and/or polymeric material. The membrane has a permeation flux of greater than 1000 GPU and a selectivity of hydrophobic molecules to hydrophilic molecules of greater than 50/1. The nanoporous material comprises pores having a pore size of 0.5-50 nm. The porous substrate comprises a ceramic material, a metallic material, and/or a porous material, and nanochannels. Each of the nanochannels has a diameter of 1-1000 nm. A portion of the nanochannels is oriented in a common direction. The nanoporous material includes nanoporous glass, nanoporous oxide, and/or anodized porous ceramic, and has hierarchical pores with diameters of 2-100 nm and a thickness of 100-10000 nm. The nanoporous material further includes a phase-separated glass, inorganic nanotubes, and diatomaceous earth particles. The nanoporous material is formed by a process comprising bonding the diatomaceous earth particles to the porous support substrate with a binder consisting of a polymeric binder and/or a sol-gel binder, etching the diatomaceous earth particles with an etchant consisting of a solvent and/or an acid to produce the nanopores and modifying the porous surface with a hydrophobic polymer/ligand material. The powder-polymer hybrid material comprises superhydrophobic diatomaceous earth particles and/or porous acrylic particles. The organic material comprises a long-chain silane molecule having 1-100C. The organic material renders the textured surface of the superhydrophobic, oleophilic or oleophobic nanoporous material. INDEPENDENT CLAIMS are included for:    (1) a method for selectively separating a substance from a solution; and    (2) a method of making a membrane structure.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a surface selective membrane.    Ethanol molecules (112)    Water molecules (113)    Superhydrophobic membrane surface (115)    Selectively permeate (116)    Nano-architectured pores layer. (117)