Rolling up graphene "omnipotent" carbon nanotubes may change the future
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In the 30 years since the discovery of carbon nanotubes, my country's research level has basically kept pace with the world's advanced level, and it has led the world in some areas.
Carbon nanotube conductive agent changes the situation that my country’s lithium battery companies rely on imports; carbon nanotube films are successfully used in high-end outdoor thermal clothing and medical rehabilitation industries; semiconductor-based carbon nanotube-based integrated circuits and display backplane drive devices Has also been developed...
Recently, Jiangsu Tiannai Technology Co., Ltd. (hereinafter referred to as Tiannai Technology), the largest domestic carbon nanotube producer, issued an announcement stating 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% over the same period last year. 357.37%.
The rapid growth in performance is attributed to the carbon nanotube conductive agent developed by the company, which has changed the situation that my country's lithium battery companies rely on imports for conductive agents.
Since they were discovered, carbon nanotubes have set off a wave of research around the world.
In recent years, the world has accelerated the exploration of the way for the implementation of carbon nanotube technology, and related technological breakthroughs have continued.
A tube with a length of meters and a diameter of nanometers
As the most important life element, "carbon" has always played a pivotal role in the evolution of life and the provision of energy.
In 1985, the "football" structure of C60 attracted 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 the electric arc method, and since then started the upsurge of carbon nanotube research.
"From the structural point of view, carbon nanotubes can be visually regarded as hollow tubular structures made of single or multilayer graphene seamlessly crimped." Suzhou Institute of Nanotechnology and Nano-Bionics, Chinese Academy of Sciences (hereinafter referred to as Suzhou Institute of Nanotechnology) ) Researcher Li Qingwen told a reporter from Science and Technology Daily.
Carbon nanotubes are like a slender hair strand. Its length can reach the meter level, but its diameter can be as small as nanometers.
How is such a slender nanotube structure made?
The carbon nanotubes that Iijima Sumio discovered for the first time were made by the arc discharge method.
At present, carbon nanotubes have developed a variety of preparation methods such as laser ablation, chemical vapor deposition (CVD), and solid-phase pyrolysis.
Among them, the CVD method is widely used because of its low cost, good controllability, and ease of large-scale preparation.
Li Qingwen introduced that when carbon nanotubes are prepared by CVD, carbon atoms are adsorbed, diffused, dissolved and saturated on the surface of the catalyst and then precipitated to form carbon nanotubes.
As a site for the nucleation and growth of carbon nanotubes, the catalyst plays a decisive role in the diameter, number of walls, and chirality of the carbon nanotubes.
Catalyst structure design and growth condition regulation are important ways to realize the controllable growth of carbon nanotubes.
As an important member of the family of carbon nanomaterials, carbon nanotubes are known as "universal substrates" for their excellent mechanical, electrical and thermal properties. Fields such as heating devices have huge application prospects.
Smalley, the 1996 Nobel Prize winner in Chemistry and the discoverer of fullerenes, believes that carbon nanotubes are the strongest, most rigid, and hardest materials that people can make, and they are also the best conductors of heat and electricity. .
"The strength of carbon nanotubes is 100 times that of steel with the same volume, but the weight is only 1/6-1/7 that of steel." Li Qingwen explained that carbon nanotubes have an aspect ratio of 106 or more, so they are also called super fibers. .
The peculiarity of carbon nanotubes also lies in their special electrical properties. Depending on their structure, carbon nanotubes can exhibit metallic and semiconducting properties, laying the foundation for the development of new electronic devices.
my country's research has reached the world's advanced level
The research on carbon nanotubes has been 30 years. Li Qingwen believes that the research level of Chinese scientists on carbon nanotubes basically keeps pace with the world's advanced level, and is at the world's leading level in some fields.
In the basic research of carbon nanotubes, the team of Zhang Jin and Li Yan of Peking University have made important contributions to the synthesis of conductive controllable carbon nanotubes and the synthesis and separation of one-handed carbon nanotubes.
Peng Lianmao's team at Peking University has made significant progress in carbon nanotube electronic devices.
In the application of carbon nanotubes, Wei Fei's team at Tsinghua University has made great achievements in the large-scale preparation of carbon nanotubes, high-strength carbon nanotube fibers, and carbon nanotube conductive additives.
As the national team for nanomaterials research in my country, Suzhou Institute of Nanotechnology has been carrying out research work around the controllable preparation and cutting-edge applications of carbon nanotubes since 2007, and published more than 300 high-level papers. Many major achievements have been made in the large-scale preparation of carbon nanotube fibers and films, carbon nanotube composite materials and energy device applications.
In 2013, the world's smallest "computer" with parallel single-walled carbon nanotubes as the main components was born.
In the past two years, the performance and size of carbon nanotube electronic devices have been breakthroughs time and time again.
How to obtain high-purity, high-quality semiconductor-type single-walled carbon nanotubes is a prerequisite for electronic-grade applications.
Li Qingwen told reporters that the team she led achieved high-concentration separation of semiconductor single-walled carbon nanotubes with purity greater than 99.99% in 2018, as well as efficient screening of some single-chiral carbon nanotubes.
On this basis, they cooperated with other domestic colleges and universities to jointly realize the development of semiconductor-type carbon nanotube-based integrated circuits and display backplane driving devices.
Carbon nanotubes, called super fibers, are made into fibers and films. Compared with traditional high-performance fibers and film materials, carbon nanotubes have excellent flexibility, electrical and thermal conductivity.
After years of research, Li Qingwen’s team has achieved the continuous preparation of kilometer-scale continuous carbon nanotube fibers, breaking through the dry-scale preparation technology of 10,000-square-meter carbon nanotube films.
At the same time, researchers from Suzhou Institute of Nanotechnology have developed a new type of carbon nanotube composite material with a carbon nanotube content of more than 60% using highly oriented carbon nanotube film, which is more than twice as strong as carbon fiber composite material; developed a carbon nanotube film The new process of electrothermal curing composite materials is expected to bring new design strategies for online composite repair and wing deicing.
Accelerated implementation of carbon nanotube research results
Carbon nanotubes, known as "black gold", were predicted by scientists to become one of the miraculous materials that "completely change the 21st century".
As the leading enterprise of carbon nanotubes in China, Tiannai Technology has successfully developed a unique catalytic reaction process to realize the continuous production of carbon nanotubes with a production capacity of 1,000 tons.
In the past two years, the shipment and sales volume of carbon nanotube conductive agent products of Tiannai Technology ranks first in the industry, which has changed the situation that my country's lithium battery companies rely on imports for conductive agents.
The use of conductive agents for lithium batteries is just the tip of the iceberg in the industrialization of carbon nanotubes.
As a national strategic emerging material, carbon nanotube materials also have a wide range of applications in conductive plastics, lightweight high-strength composite materials, wide-band lightweight electromagnetic shielding, impact protection, smart materials, and electronic devices.
Among them, the market prospects of materials such as carbon nanotube-based heating films, conductive plastics, and composite materials are getting better and better.
"While strengthening frontier exploration, we are actively carrying out research and development on the application of carbon nanotubes, and have developed lightweight carbon nanotube/metal composite wire technology and lightweight cables for satellites. The carbon nanotube heating and warm clothing developed has been obtained by many The use of international brands has become one of the Winter Olympics products." Li Qingwen said.
Based on the team's technology, Suzhou Gedi Nano Technology Co., Ltd. has realized the industrialization of carbon nanotube film, with a production capacity of 100,000 square meters per year, and successfully developed the product's application in high-end outdoor thermal clothing and medical rehabilitation.
"As an emerging material, carbon nanotubes may also be used in conductive plastics, semiconductor devices, lightweight and high-strength composite materials, broadband light electromagnetic shielding, impact protection, smart devices and other fields in the future, and are expected to bring them to these fields. Transformative development." Li Qingwen said.
Our reporter Zhang Ye