If there is a problem, we will solve it.

Graphene is considered as the most potential and the thinnest known anticorrosion material because of its excellent chemical stability and impermeability. Chemical vapor deposition (CVD) is often used to prepare large-area and high-quality graphene films. However, researchers have found that different types and sizes of intrinsic defects, such as vacancies, pinholes, cracks and graphene island boundaries, will inevitably be introduced in the process of growing graphene by CVD. The existence of defects leads to the direct exposure of metal matrix to corrosive medium, which leads to galvanic corrosion between metal matrix and graphene and accelerates the corrosion rate of metal matrix. Defects will not only reduce the corrosion resistance of graphene films, but also reduce the electrical properties, especially the electrical properties after corrosion.

At present, there are some methods to repair graphene defects, such as depositing passive oxides (such as ZnO and Al2O3) on graphene by atomic layer deposition (ALD). Oxide covering the whole graphene surface can improve the corrosion resistance of graphene films. However, ALD method takes several hours and has no high selectivity for defects, and oxides deposited in defect-free areas of graphene often significantly reduce the electrical properties of graphene. Up to now, the biggest challenge to repair graphene defects is high efficiency and high precision, without affecting its chemical stability and electrical properties.

(The content of the article comes from the Internet)

For many micro-devices working in corrosive environment, both excellent corrosion resistance and good electronic properties are needed, so economic and effective defect passivation/repair technology is urgently needed. Once any corrosive medium passes through the defects of graphene and reaches the interface between graphene and copper substrate, the galvanic corrosion process will start rapidly at the graphene/copper interface, thus accelerating the corrosion of anode copper. Although graphene often shows effective protection in the short-term corrosion and oxidation process, it may promote corrosion in the long-term corrosion test, and the resulting wet corrosion may even be more serious than the natural oxide film on copper surface without graphene layer. Most importantly, the biggest challenge is to accurately repair various defects of graphene without affecting its superior inherent characteristics, such as good chemical stability and high electronic conductivity.

Technically, there is still a lack of simple treatment methods to accurately repair all structural defects of different types and sizes on graphene in a short time (for example, about 15 minutes), and it will not cause unnecessary adsorption and adverse effects on graphene.

Recently, the team of material coupling damage and life extension in the marine laboratory of Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences has designed a fast and accurate method to repair graphene defects, which can efficiently repair multi-scale and multi-type defects on graphene within 15 minutes, and improve the anticorrosion performance of graphene films without affecting the excellent conductivity of graphene.

Graphene thin film

Can absorb more than 90% of solar energy.

Recently, researchers at the Technology Center of swinburne University in Melbourne, Australia, developed a new graphene film, which CTAM absorb more than 90% of sunlight and eliminate most of the infrared heat emission loss. This is the first report of this feat. This is an efficient solar heating metamaterial, which can be quickly heated to 83 degrees Celsius (18 1 Fahrenheit) in an open environment with minimal heat loss. The proposed applications of the film include thermal energy collection and storage, photothermal power generation and seawater desalination.

In this regard, Professor Jia, the founding director, said that it is very important for an efficient solar heat absorber to absorb sunlight while suppressing thermal radiation loss (also known as blackbody radiation), but it is extremely difficult to achieve this goal. She explained: "This is because the emission temperature is different according to the absorbed heat and the characteristics of the absorber, which leads to significant wavelength differences. However, we have developed a graphene metamaterial with a three-dimensional structure, which is highly absorbent and can selectively filter out blackbody radiation. "

(The content of the article comes from the Internet)

This three-dimensional graphene metamaterial consists of an alternating graphene film with a thickness of 30 nanometers and a dielectric layer deposited on the trench-like nanostructure, which also serves as a copper substrate to enhance absorption. More importantly, the substrate is patterned into a matrix arrangement to make the wavelength selective absorption flexible and adjustable. This new material also greatly reduces the thickness of the thin film to one third, and uses less graphene, and its thinness helps to transfer the absorbed heat to other media more effectively, such as water. In addition, the thin film is hydrophobic, which is helpful for self-cleaning, while the graphene layer effectively protects the copper layer from corrosion and helps to prolong the life of the metamaterial.

"Because the structural parameters of the metal substrate are the main factors controlling the overall absorption performance of SGM, rather than its inherent characteristics, different metals can be used according to the application requirements or costs," said Ken Lint, a researcher at Swinburne University and the main author of a paper on metamaterials recently published in Nature News. He pointed out that aluminum foil can also be used to replace copper without affecting its performance. "We used the prototype film to produce clean water and achieved an impressive solar steam efficiency of 96.2%. This is very competitive for clean water power generation using renewable energy. "

He added that this metamaterial can also be used in energy collection and conversion applications, steam power generation, wastewater purification, seawater desalination and photothermal power generation. But it is still a challenge to find a manufacturing method to make the substrate extensible.

Graphene material

Can you solve the chip problem?

The chip industry has developed for more than half a century, and the technology is constantly advancing. From micron to nanometer, it has been compressed from 90nm to 5nm in the field of nanotechnology, and it will even break through higher technology in the future. However, due to physical rules, traditional silicon materials may not be able to support the chip to break below 3nm, and the production of high-end chips is highly dependent on mask aligner. Judging from the current domestic progress, the localization of high-end chips will not be solved for a while. But if China Core adopts another material mode, it may be able to change lanes and overtake. What material is this? Graphene ~

After long-term research and development, chip manufacturing has solved a series of technical problems. In terms of materials and equipment. , has been a steady supply. Coupled with the chip foundry technology mastered by chip manufacturers, chips of various types and different processes can be successfully produced. The traditional silicon-based chip is made of silicon, which has supported the development of the industry for decades and completed several generations of technological breakthroughs from low-end to high-end.

(The content of the article comes from the Internet)

But further development, silicon-based chips may not work. 3nm, 2nm, 1nm or even more advanced processes, can silicon be used as the process material? If you want to break the restrictions of physical rules, it may not be possible to rely on silicon materials. At this time, exploring the development mode of new materials has become a new way out. At present, it has entered the third generation of semiconductor materials, and materials such as silicon carbide and gallium nitride have become the focus of market attention. However, these materials are difficult to be applied to high-end electronic consumer products. Silicon carbide is suitable for 5G equipment and new energy vehicles, while gallium nitride is widely used in chargers and other equipment. If you want to replace silicon material, it is unlikely. So is there a material that not only has excellent performance, but also can replace silicon-based chips? Perhaps graphene has become an option.

First of all, it should be clear that graphene is a two-dimensional carbon material, which is characterized by strong conductivity and is widely used in optics, mechanics, electricity and other fields. At the same time, it is applied to the development of micro-nano processing and energy industries. Because of the extensive use of graphene, it is also boasted by many people. For example, using graphene batteries is not only fast to charge, but also very safe. Unrealistic things like this are basically advocating the performance of graphene. Although graphene is widely used, it still needs time to explore if it wants to play its real value in various industries.

However, in the field of semiconductor industry, China researchers have successfully produced 8-inch graphene wafers. This is a rare example in the industry to verify that graphene can be made into wafers, which can be cut into chips and then packaged. In terms of performance, due to the strong conductivity of graphene, the transistor will have higher working efficiency. In the same process, the carbon-based chip made of graphene is 10 times that of silicon-based chip.

Although it is biased towards the theoretical effect, the appearance of 8-inch graphene wafer has developed a preliminary possibility, and perhaps China Core's lane change overtaking may be pinned on graphene. Equally important, because its performance is ten times that of silicon-based chips, even mask aligner, which has a low technological process, can produce chips with performance comparable to that of high-end mask aligner. Or let SMIC directly avoid mask aligner and use ordinary equipment to make chips.

Understand the characteristics of graphene

Research and Development on the Safety of Glove Box

Graphene (graphene)

Is it a carbon atom with sp? Hybrid orbitals form hexagonal two-dimensional carbon nanomaterials with honeycomb lattice.

Graphene has excellent optical, electrical and mechanical properties, and has important application prospects in the fields of material science, micro-nano processing, energy, biomedicine and drug delivery, and is considered as a revolutionary material in the future. Physicists Andrei Grimm and Konstantin Novoselov of the University of Manchester in England successfully separated graphene from graphite by micromachining, so * * * won the 20 10 Nobel Prize in Physics. However, as a new material, graphene still has some special chemical properties:

1, biocompatibility: carboxyl ion implantation can make the surface of graphene material have active functional groups, thus greatly improving the cellular and biological reactivity of the material. Compared with tubular carbon nanotubes, graphene is more suitable for the study of biomaterials. Moreover, compared with carbon nanotubes, graphene has longer edges, is easier to be doped and chemically modified, and is easier to accept functional groups.

2. Oxidation: It can react with active metals.

3. Reducibility: It can be oxidized in air or with acid. Graphene can be cut into small pieces by this method. Graphene oxide is a layered material obtained by graphite oxidation. It is easy to form a separated graphene oxide lamellar structure by heating in water or ultrasonic stripping.

However, the structure of graphene is relatively stable, and the carbon-carbon bond is only 1.42. However, due to its chemical properties, it still needs a safe experimental environment: graphene glove box.

Lab2000 glove box is a high-performance, high-quality closed-loop working system, which can automatically absorb water and oxygen molecules, purify the working environment and provide 1ppm O? And h? O inert atmosphere. The system is an economical circulating purification system designed for graphene research and development, including a closed box, a transition cabin, a rotary vacuum pump and a circulating purification system integrated with a microcontroller operation panel. The inert gas purification system equipped with standard Lab2000 system is equipped with a set of purification columns (fully automatic and renewable) to purify and maintain the gas environment in the glove box.

Better experimental protection of materials