Roll up Graphene into "universal" carbon nanotubes or change the future

Since the discovery of carbon nanotubes 30 years ago, China's research level has basically kept pace with the Vanguard International Semiconductor Corporation level, and is leading the world in some fields. Carbon nanotube conductive agents have changed the situation where Chinese lithium battery enterprises rely on imports for conductive agents; Carbon nanotube films have been successfully used in high-end outdoor warm clothing and medical rehabilitation industries; Integrated circuits and display backplane driver devices based on semiconductor carbon nanotubes have also been developed
Recently, the largest carbon nanotube production enterprise in China, Jiangsu Tiannai Technology Co., Ltd. (hereinafter referred to as Tiannai Technology), announced that it is expected to achieve a net profit of 110 million to 150 million yuan in the first half of 2021, an increase of 235.41% to 357.37% year-on-year. The rapid growth of performance is attributed to the carbon nanotube conductive agent developed by the company, which has changed the situation where Chinese lithium battery enterprises rely on imports for conductive agents.
Since its discovery, carbon nanotubes have sparked a research boom worldwide. In recent years, the global acceleration in exploring ways to implement carbon nanotube technology has led to continuous breakthroughs in related technologies.
A tube with a length of meters and a diameter of nanometers
As the most important element of life, "carbon" has always played a crucial role in the evolution of life and the provision of energy. In 1985, the C60 with a "football" structure caught the attention of the world as soon as it was discovered. In 1991, Japanese physicist Sumio Iijima observed carbon nanotubes in carbon materials prepared by arc method, which started the upsurge of carbon nanotube research.
"Structurally, carbon nanotubes can be seen as a hollow tubular structure made of single-layer or multi-layer Graphene seamlessly coiled." Li Qingwen, a researcher at the Chinese Academy of Sciences Suzhou Institute of Nanotechnology and Nanobionics (hereinafter referred to as Suzhou Institute of Nanotechnology), told Science and Technology Daily.
Carbon nanotubes are like a slender strand of hair, with a length of up to meters but a diameter as small as nanometers. How was such a slender nanotube like structure prepared?
The carbon nanotubes first discovered by Sumio Iijima were made by arc discharge method. Nowadays, carbon nanotubes have developed various preparation methods such as laser ablation, chemical vapor deposition (CVD), and solid-state pyrolysis. Among them, the CVD method is widely used due to its low cost, good controllability, and ease of large-scale preparation.
Li Qingwen introduced that when preparing carbon nanotubes using CVD, carbon atoms adsorb, diffuse, dissolve, and reach saturation on the catalyst surface before precipitation to form carbon nanotubes. As a site for the nucleation and growth of carbon nanotubes, catalysts play a decisive role in the diameter, wall number, and chirality of carbon nanotubes. The design of catalyst structure and the regulation of growth conditions are important ways to achieve controllable growth of carbon nanotubes.
As an important member of the family of nano carbon materials, carbon nanotubes are known as "universal substrates" due to their excellent mechanical, electrical, and thermal properties. They have enormous application prospects in fields such as structurally functional integrated composite materials, battery electrodes, integrated circuits, sensor devices, and electric heating devices.
Smoley, the Nobel Prize in Chemistry winner in chemistry in 1996 and the discoverer of Fullerene, believes that carbon nanotubes are the strongest, stiffest and hardest materials that people can make, and also the best thermal and electrical conductors.
Carbon nanotubes have a strength 100 times that of homogeneous steel, but their weight is only 1/6-1/7 that of steel. "Li Qingwen explained that carbon nanotubes have a aspect ratio of over 106, hence they are also known as super fibers.
The uniqueness of carbon nanotubes lies in their unique electrical properties. Depending on their structure, carbon nanotubes can exhibit both metallic and semiconductor properties, laying the foundation for the development of new electronic devices.
China's research has reached the Vanguard International Semiconductor Corporation level
It has been 30 years since the research of carbon nanotubes. Li Qingwen believes that the research level of Chinese scientists in carbon nanotubes is basically on a par with Vanguard International Semiconductor Corporation level, and is in the world's leading level in some fields.
In terms of basic research on carbon nanotubes, Zhang Jin's team and Li Yan's team from Peking University have made important contributions in the synthesis of conductive controllable carbon nanotubes, as well as the synthesis and separation of chiral carbon nanotubes. The Peng Lianmao team of Peking University has made significant progress in carbon nanotube electronic devices. In terms of carbon nanotube applications, the Wei Fei team from Tsinghua University has achieved remarkable results in the macro preparation of carbon nanotubes, high-strength carbon nanotube fibers, and conductive additives for carbon nanotubes.
As a national team in the field of nanomaterials research in China, Suzhou Institute of Nanotechnology has been conducting research on the controllable preparation and cutting-edge applications of carbon nanotubes since 2007, publishing over 300 high-level papers. It has achieved significant results in the separation of electronic single-walled carbon nanotubes, the preparation of carbon nanotube fibers and thin films, carbon nanotube composites, and energy device applications.
In 2013, the world's smallest "computer" was born, with parallel arranged single-walled carbon nanotubes as the main component. In the past two years, the performance and size of carbon nanotube electronic devices have been repeatedly surpassed.
How to obtain high-purity and high-quality semiconductive single-walled carbon nanotubes is a prerequisite for achieving electronic level applications.
Li Qingwen told reporters that her team achieved high concentration separation of semi conducting single-walled carbon nanotubes with a purity greater than 99.99% in 2018, as well as efficient screening of some single chiral carbon nanotubes. On this basis, they collaborated with other domestic universities and institutes to jointly develop integrated circuits and display backplane driver devices based on semiconductor carbon nanotubes.