Monochromatic Carbon Nanotube Tangles Grown by Microfluidic Switching between Chaos and Fractals

• Published in: ACS nano Vol. 15; no. 3; pp. 5129 - 5137
• Main Authors: Zhu, Zhenxing, Wei, Nan, Yan, Bowen, Shen, Boyuan, Gao, Jun, Sun, Silei, Xie, Huanhuan, Xiong, Hao, Zhang, Chenxi, Zhang, Rufan, Qian, Weizhong, Fu, Song, Peng, Lianmao, Wei, Fei
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 23.03.2021
• Subjects: self-assembly; fractal and chaos; selective synthesis; ultralong carbon nanotubes; electronic devices
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.0c10300

The nature of chaos is in that elusive flow that is an advanced order out of our vision. It is wise to take advantage of chaos after recognizing or modifying its unique fractal properties. Here, a magnetron weaving strategy was developed for producing chaotic but monochromatic carbon nanotube tangles (CNT-Ts) under Kelvin–Helmholtz instability (KHI). The self-similarity characteristic facilitated individual ultralong CNTs to manipulate their entropy-driven fractal geometry, resulting in ∼104 μm2 CNT-Ts with variable curvature radius. In addition, based on the rate-selected mechanism, 85% metallic and ∼100% semiconducting CNT-Ts were synthesized and separated simultaneously at different length positions. After ex situ modifying their fractal into aligned CNTs with hydrogel, these CNT-Ts delivered a current of 10 μA μm–1 in transistors with an on/off ratio >107. It has provided the third route as a paradigm of applying one-dimensional nanomaterials by switching between chaos and fractal, in parallel with that of direct synthesis and postseparation.