Nanoporous membranes and methods for making the same
A method for making a nanoporous membrane is disclosed. The method provides a composite film comprising an atomically thin material layer and a polymer layer, and then bombarding the composite film with energetic particles to form a plurality of pores through at least the atomically thin material layer. The nanoporous membrane also has a atomically thin material layer with a plurality of apertures therethrough and a polymer film layer adjacent one side of the graphene layer. The polymer film layer has a plurality of enlarged pores therethrough, which are aligned with the plurality of apertures. All of the enlarged pores may be concentrically aligned with all the apertures. In one embodiment the atomically thin material layer is graphene.
1. A method for making a nanoporous membrane, comprising:
providing a composite film comprising an atomically thin material layer and a polymer film;
bombarding said composite film with energetic particles to form a plurality of pores through said atomically thin material layer and a plurality of tracks of chemical functionality through said polymer film; and
etching said tracks to produce a plurality of enlarged pores in said polymer film, wherein a number of the enlarged pores in said polymer film are aligned with pores through said atomically thin material layer, wherein the polymer film is non-porous prior to being bombarded with energetic particles.
2. The method according to claim 1 , wherein each of said plurality of enlarged pores are substantially aligned with one of said plurality of pores through said atomically thin material layer.
3. The method according to claim 1 , wherein said plurality of pores through said atomically thin material layer range in size from 0.5 nm to about 10 nm, wherein said plurality of enlarged pores range in size from 10 nm to 1000 nm, and wherein said plurality of enlarged pores have a diameter larger than said plurality of pores.
4. The method according to claim 1 , further comprising:
controlling the bombarding and etching so that said plurality of enlarged pores have a diameter larger than said plurality of pores.
5. The method according to claim 1 , further comprising:
providing said atomically thin material layer as a single atomic layer of carbon material.
6. The method according to claim 1 , further comprising:
providing said atomically thin material layer as multiple atomic layers of carbon material.
7. The method according to claim 1 , further comprising:
utilizing polycarbonate as said polymeric film.
8. The method according to claim 1 , further comprising:
chemically bonding said atomically thin material layer to said polymer film during bombarding.
9. The method according to claim 1 , wherein said plurality of pores through said atomically thin material layer range in size from about 0.5 nm to about 10 nm.
10. The method according to claim 1 , further comprising:
selecting said atomically thin material from the group consisting of graphene, few layer graphene, molybdenum disulfide, boron nitride, hexagonal boron nitride, niobium diselenide, silicene, and germanene.
11. The method according to claim 1 , wherein the thickness of the polymer film is from 25 micrometers to 250 micrometers.
12. The method according to claim 1 , wherein the polymer polymer layer is of polycarbonate, polyester, polyimide, polypropylene, polyvinylidene fluoride or poly methyl methacrylate.
13. The method according to claim 1 , wherein the energetic particles are ions.