In 2004, physicists AndreGeim and KonstantinNovoselov from Manchester University in England successfully separated graphene from graphite flakes in the laboratory. Both of them won the 20 10 Nobel Prize in Physics for their pioneering experiments in two-dimensional graphene materials. It is found that its thickness is only 0.34 nm, and a graphite sheet with a thickness of 1 mm is made of nearly 3 million layers of graphene stacked.
The appearance of graphene has aroused worldwide research upsurge, especially its unique properties. Many experts call it "changing the material of 2 1 century" and predict that "2 1 century will be the century of carbon (c)".
Graphene has super conductivity, and its mobility is 100 times that of silicon. According to experts, when electrons in graphene move in orbit, they will not be scattered due to lattice defects or the introduction of foreign atoms, and the interference is very small. Therefore, the velocity of electrons exceeds that in other metal monomers or semiconductors, and can reach 1/300 of the speed of light.
The thermal conductivity of graphene is superior to that of carbon nanotubes and dozens of times that of copper, aluminum and other metals, which makes graphene a promising heat dissipation material for future VLSI. Graphene is also harder than diamond, its mechanical strength is 100 times that of steel, and it also has the flexibility of stretching and folding and excellent light transmittance, with the light transmittance reaching 97.4%.
In addition, graphene has a very high specific surface area. The ideal specific surface area of single-layer graphene can reach 2630m2/g, while that of ordinary activated carbon is1500m2/g, which makes graphene a potential energy storage material.
Broad application prospect
Graphene, which has just been born, is a carbon material with very high technical content and wide application potential. It has broad application prospects in touch screens, electronic devices, energy storage batteries, displays, sensors, semiconductors, aerospace, military industry, composite materials, biomedicine and other fields, and will become the next trillion-dollar emerging industry once it is mass-produced.
"At present, from the perspective of the whole world, graphene is a cutting-edge research, and the research and development of materials is still in its infancy. There is still a long way to go before large-scale application, but this does not mean that it is far away." Wang Xinran, a professor at the School of Electronic Science and Engineering of Nanjing University, said that graphene touch screens on mobile phones, tablets and other terminals should be the first to enter the market, and it is expected to be available in two years. Photoelectric devices such as photodetectors and solar cells made of graphene will also gradually enter the market in 20 15. However, high-frequency circuits and logic circuits with higher requirements and stricter technology will not be able to enter the market in the distant future.
Gao Hongjun, an academician of the Chinese Academy of Sciences, also said that graphene has attractive application prospects in future electronic devices, and is regarded as the most likely breakthrough and industrialization field of graphene research, which has become the focus of international research and competition.
According to media reports, a few days ago, Chongqing Institute of Green Intelligent Technology of Chinese Academy of Sciences has successfully prepared the first 15-inch single-layer graphene in China, and its size has reached the highest level in China. At present, Chongqing Research Institute of Chinese Academy of Sciences has grown 15 inch uniform single-layer graphene on copper foil substrate and successfully transferred it to the surface of flexible PET substrate. After further processing, a 7-inch graphene touch screen was made. Stick the graphene touch screen on the display screen of an ordinary notebook computer, and you can write on the screen with a stylus.
Graphene is expected to play an important role in the development of lithium-ion batteries and supercapacitors in the field of energy storage. Graphene has excellent conductivity and flexible two-dimensional layered structure, which can improve the charging and discharging speed, cycle stability and safety of lithium-ion batteries and supercapacitors, and may be fully charged in a few minutes or even seconds. This graphene lithium battery has a great market in consumer electronics, electric vehicles, energy storage and other fields.
In addition, the heat dissipation film made of graphene can be applied to ultra-thin and high-power electronic products such as smart phones, tablet computers, LED lighting and LCD TVs. Functionalized graphene materials also have high application value in biomedicine, biological diagnosis and food processing.
The investment craze is heating up.
Due to the huge market potential of graphene, the research and development and investment boom of graphene has been set off around the world. At present, Samsung Electronics, IBM, Dow Chemical, General Motors, Xerox and other international big-name manufacturers are actively promoting the research of graphene industrialization.
Data show that there are more than 200 companies involved in graphene research and development, and China and the United States are far ahead in the number of product patents. According to the latest data from CambridgeIP, a British science and technology strategic organization with in-depth research on graphene industry, the largest patent holders of 10 graphene in the world are IBM, KAIST, KIST, Rice University, Samsung, Sheng Di, Tsinghua University, Sungkyunkwan University, Xerox and Zhejiang University.
Donock, Chairman of Cambridge Intellectual Property Company, said that in the past few years, there has been a significant increase in graphene patent activities in Asia, especially in South Korea and China.
In China, Zhejiang University, Tsinghua University, Peking University, Institute of Metals of Chinese Academy of Sciences, Ningbo Institute of Materials of Chinese Academy of Sciences, Shanghai Jiaotong University, Southeast University, Tianjin University and other universities and scientific research institutions have applied for many patents in the field of graphene preparation and application.
As of June this year, domestic institutions * * * have applied for more than 3,000 invention patents related to graphene, including 456 patents authorized by China National Intellectual Property Administration, mainly focusing on the preparation and application of graphene.
In the industrial application of graphene, Jiangsu is at the forefront of the country. On July 20 10, Taizhou established the first professional graphene new material company in China, and now it has a large scale.
In 20 1 1 year, the graphene research team led by Liu Zhaoping, a researcher from Ningbo Institute of Materials, Chinese Academy of Sciences, successfully developed a low-cost large-scale preparation technology of graphene with independent intellectual property rights, and established a ton-scale pilot production line. 20 12 transferred the technology to Shanghai Nanjiang (group) co., ltd., and both parties established Ningbo moxi technology co., ltd., dedicated to the production, sales and applied technology research and development of graphene. The graphene production line with an annual output of 300 tons is scheduled to be completed by the end of 20 13.
Touch panel industry is becoming another important direction for Chongqing to develop electronic information high-tech industry. It is predicted that by 20 15, the demand for large-size touch screens for tablet computers will also reach 230 million, among which graphene will occupy an important market. To this end, Shanghai Nanjiang Group will jointly promote the "large-scale single-layer graphene industrialization project" with Chongqing Research Institute of Chinese Academy of Sciences, with an initial investment of 267 million yuan. Recently, the graphene industrial base has successfully settled in Chongqing, and will strive to build the first production line and put it into production within one year, forming a production capacity of 6,543,800 graphene sheets.
With the technological progress and industrialization of graphene, the market pays more and more attention to it. Dozens of high-tech enterprises involved in research and development, production, sales and service of graphene have emerged. For example, Shanghai Xinchi, Nanjing Foucault Nano, Shenzhen Betray and so on. Among them, many venture capital institutions actively participate.
In addition, many domestic listed companies have also entered the field of graphene applications. Fangda Carbon announced on the evening of May 20th that its method of preparing graphene from limestone has recently obtained a patent certificate from China National Intellectual Property Administration with a patent period of 20 years. Fangda Carbon indicates that compared with the prior art, the invention has the advantages of simple preparation process, wide source of raw materials, low cost, safety and environmental protection.
Yunhua Chen, Chairman of Da Yue Investment Board, revealed in March this year that the company is currently planning the research and development of graphene products, which will be mainly used in textile and garment, automobile batteries, mobile phones and other fields; 20 13 March, Du Nan Electric Power Company announced that it had formally applied for two patents of graphene and graphene battery. 20 12 July, Gorgeous Family confirmed that Nanjiang Group, the controlling shareholder, was investing in the construction of the world's first graphene production line. Zhong Chao Cable recently confirmed that in July of 20 12, the company obtained the effective patent of "Rubber Insulated Cable with Graphene"; The "Large-scale Preparation Technology of Graphene Materials" jointly developed by Lu Jin Group and Institute of Metals, Chinese Academy of Sciences has passed the expert appraisal of Sichuan Science and Technology Department.
Obstacles to industrialization
Although the research and development of graphene is in full swing, it is highly sought after in academia, business circles and capital markets, but how to prepare graphene with high quality, large size and low cost on a large scale is an urgent problem to be solved in industrialization.
At the forum on the development trend and investment of graphene industry held in July 13, many experts said that the technology for preparing graphene at present is not mature, and the product area is very small, which can not adapt to industrial applications. Graphene as a whole is still in the research and development stage, and countries are in the patent layout period for this emerging material, and the industrial chain has not yet formed. The greatest demand for graphene is still the research and application of major universities and scientific research institutions.
According to reports, the reason why graphene has not been mass-produced is because it has not found a method and way suitable for mass production, which is also the reason why the cost of graphene remains high. At present, there are four main preparation methods of graphene: micro-mechanical stripping, epitaxial growth, graphite oxide reduction and chemical vapor deposition.
The method of obtaining graphene by Nobel Prize winners Heim and Novoselov is called micro-mechanical stripping, that is, cutting graphene sheets directly from larger crystals. This method is still an important means to obtain graphene in the laboratory for basic research. Graphene obtained by this method is of high quality, but its size is small and different, and its labor intensity is high and its cost is high, which can not meet the needs of industrialization.
Graphene obtained by epitaxial growth method has large area and high quality, but the disadvantage is that the production cost of graphene is very high and the growth conditions are very harsh. Graphene generated by this method is not easy to transfer to other substrates, because it is very difficult to grow graphene on a metal surface and then transfer it to a suitable substrate, just like spreading a thin plastic wrap on a football field to make it flat and complete.
At present, graphite oxide reduction method is the lowest cost and the easiest way to produce graphene on a large scale. Its disadvantage is that in the redox process, the electronic structure and crystal integrity of graphene are easily destroyed by strong oxidants, which further affects the molecular characteristics of graphene.
Although chemical vapor deposition can prepare graphene in a large area and it is not difficult to transfer it to other substrates, the quality still needs to be improved, and the process is more complicated and the cost is higher.
The research on graphene in China started late, but it followed quickly. By the end of 20 12, the number of graphene-related research papers has reached 5072, surpassing the United States and ranking first in the world.
"But we have two shortcomings. First of all, although the research group is huge and there are many achievements, there are few excellent and original achievements. We have always been in a backward position by adopting mature methods of others, and the major innovation is very limited. We should seek a breakthrough in the preparation methods of materials. In addition, it mainly focuses on basic research, and its industrial application is relatively weak. " Gao Hongjun, an academician of China Academy of Sciences, said that enterprises from Europe, the United States, South Korea and other countries participated earlier, and the application and transformation of their achievements also took the lead in the world.
Zhu Hongwei, from the graphene research team of Professor Kang Feiyu of Tsinghua University, believes that graphene has the capability of mass production at present, but there are still some problems in its development. China's existing technical level can support its industrialization, but it has not reached the best level, and it needs a big breakthrough in the future. However, there is still a gap between the preparation technology of graphene and the ideal state. In addition, he hopes that the state can give more policy support to graphene research institutions and enterprises.
Ni Zhenhua, a professor and doctoral supervisor of Southeast University, put forward five suggestions on accelerating graphene research and industrialization: First, guide the correct direction of graphene research from the government level; Second, accelerate the process of industrialization through policy support; The third is to establish industry standards as soon as possible and strive for the right to speak; Fourth, strengthen exchanges and cooperation between industries to promote the wide application of graphene; The fifth is to establish relevant industrial technology alliances and strengthen coordination and cooperation within the industry.
In recent years, the rise of graphene has also attracted the attention of the government of China. Last year, the Ministry of Industry and Information Technology issued the Twelfth Five-Year Development Plan for New Materials Industry, which listed graphene as a cutting-edge new material. In addition, a number of major projects have been deployed in the national science and technology major projects and the national 973 plan.
At the 20 13 graphene industry development trend and investment forum, Gao, deputy director of the raw materials department of the Ministry of Industry and Information Technology, said that graphene belongs to the category of nanomaterials. When the Twelfth Five-Year Development Plan of the new materials industry was compiled, graphene was not as popular as it is now, and the industrial application prospect was not clear. Therefore, graphene is not the main concern in the planning text and product catalogue, but with the breakthrough of technology and application, it will be studied and considered in the next step.
13 In July, China's strategic alliance for technological innovation of graphene industry was established in Beijing. The establishment of the alliance will help to integrate and coordinate industrial resources, establish a resource sharing mechanism for upstream and downstream information and intellectual property rights in Industry-University-Research, further enhance the overall innovation level of graphene industry chain and the competitiveness of low-cost graphene, and promote the healthy development of graphene industry in China.