Covalent reinforcement of carbon nanotube assemblies
Disclosed here is a method of fabricating a covalently reinforced carbon nanotube (CNT) assembly. The method includes producing a CNT assembly by pulling entangled CNTs from a CNT array fabricated on a substrate, the CNT assembly including a plurality of CNTs that are aligned; and creating covalent bonding between the CNTs of the CNT assembly by applying a high energy ion irradiation to the CNT assembly.
1. A carbon nanotube (CNT) based material, comprising:
a plurality of CNTs that are aligned, the adjacent CNTs of the plurality of CNTs are covalently bonded through defects created by a high energy ion irradiation such that the CNT based material has a Young's modulus that is at least about 5 GPa greater than that of an untreated CNT based material, dosage of the high energy ion irradiation is from about 10 13 ions per cm 2 to about 10 16 ions per cm 2 ;
wherein adjacent CNTs of the plurality of CNTs are covalently bonded between each other, and the adjacent CNTs of the plurality of CNTs are covalently bonded through defects created by the high energy ion irradiation such that the Young's modulus is not monotonic relative to the dosage as the dosage increases and an intensity of a D band of Raman spectroscopy of the CNT based material is greater than an intensity of a G band of the Raman spectroscopy of the CNT based material.
2. The CNT based material of claim 1 , wherein the plurality of CNT form one or more CNT yarns or one or more CNT sheets.
3. The CNT based material of claim 2 , wherein the CNT sheets are overlaid in multiple orientations.
4. The CNT based material of claim 1 , wherein the adjacent CNTs of the plurality of CNTs are covalently bonded through defects created by a high energy ion irradiation.
5. The CNT based material of claim 4 , wherein the high energy ion irradiation includes an irradiation of 4He+ ions having an energy level of about 1-10 MeV with a dosage of from about 10 13 ions per cm 2 to about 10 16 ions per cm 2 .
6. The CNT based material of claim 1 , wherein the plurality of CNTs are densified by wet-densifying using a solvent or exposing the CNTs to a mist or aerosol of at least one solvent.
7. The CNT based material of claim 1 , wherein the plurality of CNTs form a plurality of sheets having a thickness greater than or equal to 1 μm and less than or equal to 10 μm.
8. A carbon nanotube (CNT) based material, comprising:
a plurality of CNTs that are aligned, wherein adjacent CNTs of the plurality of CNTs are covalently bonded between each other through defects created by irradiation by 4 He + ions from about 10 13 4 He + ions per cm 2 to about 10 16 4 He + ions per cm 2 such that the CNT based material has a Young's modulus that is at least about 5 GPa greater than that of a CNT based material not treated by irradiation and that is not monotonic relative to the irradiation as the irradiation is increased between about 10 13 4 He + ions per cm 2 and about 10 16 4 He + ions per cm 2 , and an intensity of a D band of Raman spectroscopy of the CNT based material is greater than an intensity of a G band of the Raman spectroscopy of the CNT based material.