Ion Beam Modification of Carbon Nanotube Yarn in Air and Vacuum

Jonathan G Gigax; Philip D Bradford; Lin Shao

doi:10.3390/ma10080860

Ion Beam Modification of Carbon Nanotube Yarn in Air and Vacuum

Materials (Basel). 2017 Jul 27;10(8):860. doi: 10.3390/ma10080860.

Authors

Jonathan G Gigax¹, Philip D Bradford², Lin Shao³

Affiliations

¹ Department of Nuclear Engineering, Texas A&M University, College Station, TX 77843, USA. gigaxj@tamu.edu.
² Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695, USA. philip_bradford@ncsu.edu.
³ Department of Nuclear Engineering, Texas A&M University, College Station, TX 77843, USA. lshao@tamu.edu.

Abstract

We studied the effects ion beam irradiation on carbon nanotube (CNT) yarns. CNT yarn was fabricated by drawing and spinning CNT sheets from a vertically aligned CNT forest. The yarn was irradiated by 2.5 MeV protons in either vacuum or air. Irradiation in air was achieved by directing the proton beam through a 0.025 mm thick Ti window. Irradiation in vacuum occurred at a pressure of <10^-6 torr at room temperature and at an elevated temperature of 600 °C. Tensile testing revealed that CNT yarn irradiated in air increased in tensile strength with increasing proton fluence. For yarn irradiated in vacuum, however, the strength decreased with increasing fluence. We believe that irradiation-induced excitation and trapping/bonding of gas atoms between tubes may play a role for the mechanical property changes.

Keywords: carbon nanotube yarn; carbon nanotubes; ion beam welding; ion-solid interaction.