The word "aerogel" has been increasing in frequency in recent years, and people's understanding of aerogels is also deepening. From knowing nothing about it to gradually realizing its superiority, especially after emphasizing the role of new materials strategy in the 13th Five-Year Plan, aerogel has become the focus of attention in advanced new materials.

At present, China's research work on aerogels is mainly concentrated in the Boer Institute of Solid Physics, Tongji University, National University of Defense Technology, Tsinghua University, Zhejiang University, Harbin Institute of Technology, etc. At the same time, the professionalism of Chinese colleges and universities in the field of aerogel research and the ability of domestic companies to explore the technology of reducing aerogel manufacturing costs have been the continuously strengthened, and they have begun to advance to the world's advanced level and enter the world's advanced ranks.

Tongji University helps research and development in the field of aerogels

In 1931, Kistler of Stanford University prepared aerogel by hydrolyzing water glass, but because of the high production cost, it has not received widespread attention. In the 1980s, some physicists in Europe began to study this new material. In 1985, the Institute of Physics of the University of Wurzburg organized the first "Aerogel International Symposium". In the early 1990s, the United States resumed research on the aerogels.

Tongji University also began research on aerogels in the 1990s, which can be said to be the earliest batch of research institutes in China to study aerogels. Aerogel is composed of more than 90% air and less than 10% solids. Aerogel is the most dense in the world

One of the small solids, the density is only 3 kg per cubic meter. The special nanopores and network structure of aerogels exhibit many excellent physical and chemical properties and functions. Ni Xingyuan said, "We at the Institute of Solid Physics of Tongji University first started to study the application of the physical properties of aerogels. At present, most of the researches on the functions of aerogels are based on physical functions. At present, Tongji University Research on the function of aerogels has focused on thermal, optical, electrical, acoustic, and mechanics (such as explosion-proof, impact resistance), etc., and has also carried out some research on chemical adsorption. "In terms of materials, we The research is relatively extensive. We have studied inorganic aerogels, organic aerogels and composite aerogels. In addition to the most common silicon aerogels, there are carbon-based, sulfur-based, metal oxide-based, metal-based, etc. Wait, Tongji University is involved in most of these areas. "

In the earliest applications, aerogel was widely used in the aerospace and military fields, because of some characteristics of aerogel, it has become an irreplaceable material in aerospace exploration, the Russian "Peace" space station and the US "Mars pathfinder" The detectors are used for insulation. At present, in addition to the aerospace field, aerogel can also be widely used in many fields such as military industry, petrochemical, power, metallurgy, construction, clothing, etc., especially as an important substitute for traditional thermal insulation materials.

Insulation is currently a hot spot for aerogel application development. When the front of the aerogel is subjected to a flame spray of more than 1000 degrees Celsius, the back can still be touched by hand. This is due to the very low thermal conductivity and refractive index of aerogels, and its insulation capacity is dozens of times better than the best glass fibers.

The promotion of aerogel should change the understanding and reduce the cost

At present, many companies in China are engaged in the research and development of aerogels, but the application of aerogels in the field of building materials has not been widely promoted. The main reason is that the price of aerogel felts is relatively high compared to existing insulation materials. Therefore, if there are no special requirements in the construction field, building designers and developers will generally not consider the use of aerogel felts as thermal insulation materials.

Compared with other thermal insulation materials, aerogel has comprehensive advantages that other materials cannot match. "Compared with other traditional thermal insulation materials, aerogel felt has lower thermal conductivity, better thermal insulation performance than other materials, and under the same environmental conditions, the better the thermal insulation performance, the more obvious the reduction in thermal insulation or insulation Thermal energy consumption; from the perspective of building structure, aerogel felt will be thinner and lighter, which can expand a large space in the area of the building. At the same time, due to the lighter product, it can reduce the building Concerns about load-bearing capacity. At the same time, aerogel composite products also have their own excellent performance in sound insulation, fire prevention, moisture resistance and other aspects. Overall, the cost performance of aerogel composite products is much higher than other insulation materials. Ni Xingyuan pointed out that in the design and development of buildings, people do not have enough knowledge about aerogel composite products. The next step is to strengthen their promotion and promotion in the field of building materials.

Of course, from the perspective of aerogel production enterprises, it is necessary to consider further reducing their production costs, to reduce the raw material cost of aerogel production and adjust the production technology of composite aerogel to tap potential. In addition, if the production of aerogel products is of considerable scale, the production cost will be further reduced. After people's awareness is strengthened and product costs are reduced, aerogels will be used in the construction field on a larger scale.