Nanoscale fiber films, composites, and methods for alignment of nanoscale fibers by mechanical stretching
Methods for aligning nanoscale fibers are provided. One method comprises providing a network of nanoscale fibers and mechanically stretching the network of nanoscale fibers in a first direction. The network of nanoscale fibers is substantially devoid of a liquid. A network of aligned nanoscale fibers and a composite comprising a network of aligned nanoscale fibers are also provided.
1. A method for aligning nanoscale fibers, the method comprising:
providing a network of nanoscale fibers, wherein the network of nanoscale fibers is a buckypaper that is substantially devoid of a liquid, and comprises carbon nanotubes that are randomly oriented;
providing a supporting medium on or in the network of nanoscale fibers; and
mechanically stretching the network of nanoscale fibers and the supporting medium in a first direction.
2. The method of claim 1 , wherein the nanoscale fibers are carbon nanotubes having an average length of at least 1 millimeter.
3. A method for aligning carbon nanotubes or other nanoscale fibers comprising:
providing a network of nanoscale fibers, wherein the network of nanoscale fibers is a buckypaper comprising carbon nanotubes that are randomly oriented;
providing a supporting medium on or in the network of nanoscale fibers; and
mechanically stretching the network of nanoscale fibers and the supporting medium in a first direction.
4. The method of claim 3 , wherein the supporting medium comprises a flexible thermoplastic material.
5. The method of claim 4 , wherein the flexible thermoplastic material comprises a polyethylene film.
6. The method of claim 3 , further comprising, after the stretching, removing the supporting medium from the network of nanoscale fibers.
7. The method of claim 6 , wherein the removing comprises thermally decomposing the supporting medium.
8. The method of claim 7 , further comprising annealing the supporting medium before the thermally decomposing.
9. The method of claim 1 , wherein the mechanically stretching is a continuous process.
10. The method of claim 3 , wherein the mechanically stretching is a continuous process.
11. The method of claim 1 , wherein the supporting medium comprises a flexible thermoplastic material.
12. The method of claim 11 , wherein the flexible thermoplastic material comprises a polyethylene film.