Airgel materials development
Airgel is the world\’s first product was prepared in 1931. At that time, Steven.S. Kistler Pacific University of California (College of the Pacific) presented to demonstrate having a solid \”gel\” continuous network structure of the same size, which is consistent with the shape of the wet gel. This simple method is contemplated to prove that the purge liquid from the wet gel without damaging the solid form. As usual route of technology, it is difficult to do this. If you simply let drying the wet gel, the gel will shrink, often original shape damage, broken into small pieces. In other words, this shrinkage is often accompanied by severe cracking of the gel. Kistler presumed: a solid gel is composed of a microporous, there is a large surface tension of the liquid-gas interface when the liquid evaporates, the surface tension pore collapse. Thereafter, Kistler discovered the key technologies (Kistler, 1932) was prepared airgel. After this discovery, with the increase added to the field researchers, aerogels science and technology has been rapid development. Here are some well-known results: (1) the early 1980s, particle physicists would recognize SiO 2 airgel is the ideal medium material Cerenkov (Cherenkov) detector, the test requires a lot of transparent SiO 2 airgel. They use TMOS method for producing the two large detectors: a detector in Hamburg, Germany TASSO DESY (Deutsches Elektronen Synchrotron) laboratory, using a 1700 l SiO 2 aerogels; the other is CERN (the CERN) probe manufactured using 1000 liters prepared from the University of Lund, Sweden (University of Lund) of Si0 2 aerogels. (2) a method using TMOS, SiO 2 aerogels prepared first in a pilot plant for bulk material (pilot plant) is Sweden Siqiao Bo (S jobo) created by researchers at the University of Lund. Plants using 3000 liters autoclave to meet supercritical methanol (240 ℃, 80 atm) high temperature and pressure required. However, the autoclave occurred in 1984 in the production process leaks within the plant quickly filled with methanol vapor, followed by an explosion. Fortunately, inThe accident caused no casualties, but the device is completely scrapped. The plant was later rebuilt, continue to use the TMOS method for producing SiO 2 airgel. Now, this plant is managed by Airglass company. (3) 1983, Berkeley Laboratory ((Berkeley Lab) Microstructure of Materials Research Group (Microstructured Materials Group) found very toxic compound TMOS available tetraethyl orthosilicate (TEOS) Alternatively, an agent of TEOS is relatively safe, TEOS is used without compromising the quality of the airgel products. (4) microstructure of materials Research group (microstructured materials group) also found that, prior to the supercritical drying, gel ethanol liquid CO 2 can be replaced, will not aerogels have a negative impact in terms of security, this is a great improvement, because the operating conditions of the CO 2 the critical point (31.0 C, 7.3MPa) than the critical point of methanol (239.40 ℃, 8.09MPa ) easy control of operation. Further, C0 2 is no risk of explosion. this technique is used for the preparation of SiO 2 airgel material made of TEOS transparent. German company BASF 2 airgel while the invention was prepared from sodium silicate SiO beads of CO 2 substitution method, this material until 1996 to start production, the trade name \”BASOGEL\”. (5) 1985, Professor Jochen Fricke Physics of the University of Newcastle in Germany Weier Zi Würzburg organized the first \”gas international Symposium gel \”(international Symposium on Aerogels, referred to as ISA) at the conference received 25 research papers were submitted from around the world. then, ISA, respectively, in 1988 in Montpellier, France, 1991 in Würzburg, Germany, the United States was held in 1994 in Berkeley, where ISA participate in the fourth meeting in 1994 of 151 personnel, 10 special reports, 51 contributors, 35 show Daily. fifth, six circles ISA conferences were held in Montpellier, France and the United States Albuquerque, New Mexico (Albuquerque) in 1997 and 2000. (6) the late 1980s, led by the Larry Hrubesh Laboratory LLNL (Lawrence Livermore National Laborato move researchers prepared the world\’s smallest CO 2 density airgel (and is the least dense solid material), aerogels the density of 0.003g / cm3, only three times the density of air. (7) US jet propulsion laboratory (jet propulsion laboratory) airgel has carried out several special assignments in space shuttle flight, these low-density aerogels are used to collect high-speed cosmic dust samples (Tsou, 1995), and the space shuttle insulation, airgel insulation material as a super attention, research and development focus shifted to the United States. (8) 1999 United States Aspen Systems company to undertake the task of NASA prepared fiber composite airgel super-insulation materials, was established in 2001 Aspen Aerogel company\’s commercial operation airgel, especially as a super open airgel insulation materials industry boom. (9) in 2004 the first in the airgel materials industry of Nano-tech company founded in 2014 in Zhejiang St. Connaught energy-saving technologies Co., Ltd. was established, we launched the most advanced technology aerogels and airgel products.