Thin layer chromatography plates and related methods
In an embodiment, a method for manufacturing a thin layer chromatography (“TLC”) plate is disclosed. The method includes forming a layer of elongated nanostructures (e.g., carbon nanotubes), and at least partially coating the elongated nanostructures with a coating. The coating includes a stationary phase and/or precursor of a stationary phase for use in chromatography. Embodiments for TLC plates and related methods are also disclosed.
1. A method for manufacturing a separation plate without the use of a separate binder, the method comprising:
forming a layer of elongated nanostructures over a substrate;
at least partially coating the elongated nanostructures with a coating, the coating including at least one of a stationary phase or a precursor of a stationary phase for use in chromatography;
oxidizing the coating so that a plurality of porous stationary phase structures are formed, the plurality of porous stationary phase structures defines respective porous elongated structures that extend longitudinally away from the substrate; and
substantially concurrently with the act of oxidizing, removing at least a portion of the elongated nanostructures that have been at least partially coated.
2. The method as recited in claim 1 , wherein the coating that at least partially coats the elongated nanostructures defines respective porous elongated annular structures that extend longitudinally away from the substrate.
3. The method as recited in claim 1 , wherein forming a layer of elongated nanostructures over a substrate comprises growing the layer of elongated nanostructures on a catalyst layer disposed on a substrate.
4. The method as recited in claim 3 , wherein the catalyst layer comprises iron.
5. The method as recited in claim 4 , wherein the catalyst layer exhibits a thickness between about 1 nm and about 5 nm.
6. The method as recited in claim 3 , wherein the catalyst layer is formed by coating substantially all of a surface of the substrate.
7. The method as recited in claim 3 , wherein the catalyst layer is formed on the substrate in a selected pattern.
8. The method as recited in claim 3 , wherein the substrate comprises a backing layer on which the catalyst layer is disposed, the backing layer including at least one material selected from the group consisting of silica, silicon, alumina, borosilicate glass, and steel.
9. The method as recited in claim 3 , wherein growing the layer of elongated nanostructures on the catalyst layer disposed on a substrate comprises growing a layer of carbon nanotubes.
10. The method as recited in claim 9 , wherein the substrate and the catalyst layer are heated to between about 700° C. and about 800° C. during the act of growing the layer of carbon nanotubes.
11. The method as recited in claim 1 , wherein at least partially coating the elongated nanostructures with a coating comprises forming the coating to include at least one material selected from the group consisting of silicon, silicon dioxide, silicon nitride, aluminum, aluminum oxide, zirconium, and zirconium oxide.
12. The method as recited in claim 11 , wherein forming the coating to include at least one material selected from the group consisting of silicon, silicon dioxide, silicon nitride, and aluminum oxide comprises at least partially infiltrating the elongated nanostructures by low pressure chemical vapor deposition with an infiltrant.
13. The method as recited in claim 12 , wherein the low pressure chemical vapor deposition process is carried out at a temperature between about 560° C. and about 600° C. and a pressure between about 100 mTorr and about 300 mTorr.
14. The method as recited in claim 13 , further comprising functionalizing the plurality of porous stationary phase structures.
15. The method as recited in claim 1 , wherein removing at least a portion of the elongated nanostructures comprises heating the elongated nanostructures in an oxidizing environment so that the elongated nanostructures are substantially removed.
16. A method for manufacturing a separation plate without the use of a separate binder, the method comprising:
forming a layer of carbon nanotubes over a substrate;
at least partially coating the carbon nanotubes with a stationary phase having a coating thickness of about 10 nm to about 100 nm;
removing at least a portion of the carbon nanotubes that have been at least partially coated; and
bonding functionalizing moieties to the stationary phase for functionalizing the stationary phase.
17. The method as recited in claim 16 , wherein removing at least a portion of the carbon nanotubes that have been at least partially coated includes oxidizing the carbon nanotubes.
18. The method as recited in claim 16 , wherein the stationary phase comprises silica.