airgel is an internal network structure filled with the gas, presenting the appearance of a very low density of the porous solid material, the solid material is the lightest. It is generally made up of a network of nanoparticles composed of mutually crosslinked, wherein the interior of the pores is mainly a microporous particles, mostly between the particles and the particles are macroporous or mesoporous on 2 nm.
The low thermal conductivity airgel
has a low density aerogels (~ 0.16 mg / cm3), high specific surface area (400 -1000 m2g-1), high porosity (90% -99.8%), low thermal conductivity (~ 0.012 Wm-1k-1), controlled architecture, and many other excellent properties, the world is called magic change material, the inclusion of since the 1990s, one of the top 10 science and technology, military and civilian applications has great value.
from the components of the classification is to distinguish between aerogels most common way, a composite component into a single component and two categories. Single component oxide airgel comprising airgel (silica and non-silica), aerogels (resin matrix and fiber group), carbon airgel (carbonized plastic, carbon nanotubes, and graphene) , sulphides and other types of airgel airgel (single element, a carbide); airgel composite component comprises multicomponent airgel, airgel gradient and micro / nano-airgel composite. Wherein the silicon airgel, carbon airgel, and silica airgel most common.
and for thermal conductivity airgel structure
Aerogels have good thermal insulation, it is the main principle: the airgel nanopores not flow freely in the air, to eliminate air convection. Airgel composition up to 80% of air, a solid content less, and thermally conductive elongated path, thereby greatly reducing the solid heat conduction. The pore size of nanopores (mostly 20-50 nm) is smaller than the free path of air molecules (70nm), greatly reduced heat transfer is formed of air molecules colliding. Large number of gas-solid interfaces, and added special opacifiers, heat radiation blocking greatly.
airgel production process
is the performance of the airgel by the structure thereof. Thus the junction of how to makeConfiguration is particularly critical, there are mainly three-step process. 1, the process solution to the sol: colloidal particles of nanoscale by condensation and hydrolysis in a homogeneous precursor solution to form, or to catalyze accelerated by catalysts. 2, the sol-gel process (gel): hand in hand the connection between the sol particles, assembled into a layered continuous wet gel having a network structure. 3, the gel into an airgel process (drying): this process the solvent in the wet gel is replaced by air, while not serious damage microstructure.
Thus there are two main production airgel key technologies: sol – gel technique and drying, the former is mainly in order to obtain a space having a network structure, which is sucked alcohol condensate gum backbone network solvent removed to obtain an airgel material. The former include: inorganic aerogels, organic aerogels, carbon aerogels sol – gel techniques, which are: Supercritical drying, subcritical drying, freeze-drying and atmospheric drying techniques.
Properties and applications of aerogels
The main properties of airgel and its application
Aerogels domestic enterprises
airgel domestic development of the industry very quickly, the company is the head enterprise. If you are interested, you can pay more attention to their dynamic. Note that this is only for the introduction of young people in need and does not constitute investment advice. If interested in this, you can choose one according to their interests and place of employment. My own experience is that big companies will provide a good platform, it is recommended to select a feel after promising big companies can investigate. If you\’re interested in and have confidence in yourself is not enough, you can first join.
1, airgel industry is a sunrise industry, market potential is great! Currently focused on the application of insulation materials, thermal insulation materials market potential. In addition, airgel market potential for other applications is also great! 2, China\’s advanced airgel technology, and the United States in direct competition in the world, learn English to become international talents. After China airgel is the trend to go out, it is recommended to learn English, prepare for internationalization. 3, choose a large enterprise, the platform is good, to learn more. I hope this article especially students inorganic non-metallic materials helpful in employment and the professional careers of the material.