Nanoporous materials consist of a regular organic or inorganic bulk phase in which a porous structure is present.
[6] Having pore diameters with length scales of molecules, such materials enable applications that require molecular selectivity such as filtration and separation membranes.
For example, microporous materials may have a few pores with 2 to 50 nm diameter due to random grain packing.
[7] Organic nanoporous materials are polymers made from elements such as boron, carbon, nitrogen, and oxygen.
In general, to create organic nanoporous materials, a monomer with greater than 2 branches (i.e. covalent bonds) is dissolved in a solvent.
After additional monomers are added and polymerization occurs, the solvent is removed and the remaining structure is considered a nanoporous material.
[11] Titania nanotubes are also used in orthopedics but are special as they can form a titanium oxide layer upon exposure to oxygen.
[14] While one may store gases in the bulk phase, such as in a bottle, nanoporous materials enable higher storage density, which is attractive for energy applications.
[15] By storing hydrogen at high densities using porous materials, one can increase electric car mileage range.
For example, measuring the electrical resistivity of a porous metal can yield the exact concentration of an analyte species in gaseous form.
[1] Since the resistivity of the substrate is proportional to the surface area of the porous media, using nanoporous materials will yield higher sensitivity in detecting trace gaseous species than their bulk counterparts.
Enzyme catalyzed reactions in biological applications are highly utilized for metabolism and processing large molecules.
Nanoporous materials offer the opportunity to embed enzymes onto the porous substrate which enhances the lifetime of the reactions for long-term implants.