Continuous growth of single-wall carbon nanotubes using chemical vapor deposition
View Patent ↗The invention relates to a chemical vapor deposition process for the continuous growth of a carbon single-wall nanotube where a carbon-containing gas composition is contacted with a porous membrane and decomposed in the presence of a catalyst to grow single-wall carbon nanotube material. A pressure differential exists across the porous membrane such that the pressure on one side of the membrane is less than that on the other side of the membrane. The single-wall carbon nanotube growth may occur predominately on the low-pressure side of the membrane or, in a different embodiment of the invention, may occur predominately in between the catalyst and the membrane. The invention also relates to an apparatus used with the carbon vapor deposition process.
1. An apparatus for conducting a chemical vapor deposition process, comprising:
a first tube and a second tube, said first tube disposed at least within a portion of the second tube, said first tube including a first opening and a second opening, said first opening facing the interior of the second tube, and said second opening being coupled to a vacuum;
a porous membrane contiguous to the first opening, said porous membrane having a first side and a second side, wherein the first side is opposite the second side and the first side faces the interior of the second tube; and
a thin catalyst composition layer is present on at least the first side of said porous membrane wherein said thin catalyst composition layer comprises alumina, iron and molybdenum in a 9:1:1/3 molar ratio.
2. The apparatus of claim 1 , wherein said porous membrane cinctures said first opening.
3. The apparatus of claim 1 , wherein said porous membrane has a pore size less than 2 micron.
4. The apparatus of claim 1 , wherein said porous membrane has a pore size less than 500 nm.
5. The apparatus of claim 1 , wherein said porous membrane comprises alumina or stainless steel.
6. The apparatus of claim 1 , wherein said membrane comprises alumina and has a pore size less than 500 nm.