Effect of Electron Beam and Gamma Rays on Carbon Nanotube Yarn Structure

Individual carbon nanotubes (CNTs) exhibit excellent mechanical, electrical and thermal properties, leading to development of a new generation of advanced lightweight materials and spacecraft electronics substituting the electronics based on silicon. The direct assembly of CNTs into macroscopic fibers or sheets has been a way to overcome their dispersion and processing challenges. Because of a wide range of applications of this material, we investigate effectively the defects on CNT yarns structures created by electron beam and gamma sources and their impact on the morphology and mechanical properties. The irradiated samples with electron beam at doses of 400, 600 and 800 kGy had a decrease in the strength from 219.60 ± 18.90 MPa for pristine yarn to 108.86 ± 23.77, 153.15 ± 21.63, 170.50 ± 25.78 MPa, respectively. The sample irradiated with gamma in air at dose of 100 kGy had the strength increased slightly as compared with the pristine sample and an increase in the elasticity modulus from 8.79 ± 1.19 to 19.63 ± 2.02 GPa as compared to CNT pristine yarn. The quality of the CNT yarns that was gamma irradiated in air with absorbed dose of 100 kGy was not affected by the radiation process with improvement of 123% of the Young’s modulus.单根碳纳米管（carbon nanotubes，CNTs）具备优异的力学、电学与热学性能，推动了新一代先进轻质材料与替代硅基电子器件的航天用电子器件的研发。将碳纳米管直接组装为宏观纤维或片材，是解决其分散与加工难题的有效途径。鉴于该材料应用范围广泛，本研究针对电子束与γ射线辐照在碳纳米管纱线结构中引入的缺陷，以及这些缺陷对其形貌与力学性能的影响开展了系统性探究。分别经400、600、800 kGy剂量电子束辐照的样品，其拉伸强度从原始碳纳米管纱线的219.60 ± 18.90 MPa依次降至108.86 ± 23.77、153.15 ± 21.63、170.50 ± 25.78 MPa。经100 kGy剂量空气中γ射线辐照的样品，其拉伸强度较原始样品小幅提升，弹性模量则从原始碳纳米管纱线的8.79 ± 1.19 GPa提升至19.63 ± 2.02 GPa。经100 kGy吸收剂量空气中γ射线辐照的碳纳米管纱线，其整体品质未受辐照工艺影响，杨氏模量增幅达123%。