Nano aerogel thermal insulation felt is a kind of controllable structure of nano porous light material, it has nano structure ( pores 1 ~ 100 nm, skeleton particles for l - 20 nm ), large surface area ( up to 800 - 1000 m2 / g ), high porosity ( up to 80 % - 99.8 % ) and so on. The unique structural characteristics of nano - si0 aerogel make aerogel have singular properties in thermal, electrical, acoustic and optical aspects. The thermal conductivity of the nano aerogel thermal insulation felt can reach below 0.013 w / ( m k ), which is far lower than the thermal conductivity of air at normal temperature of 0.025 w / ( m k ). the nano aerogel thermal insulation felt is one of the best thermal insulation properties of all solid materials, and has the advantages of low density, water resistance, flame retardance, green environmental protection, acid and alkali resistance, corrosion resistance, difficult aging and long service life, which is incomparable with other traditional materials. therefore, the nano aerogel thermal insulation felt is called a super thermal insulation material, and has great application potential in many fields, such as building energy conservation, energy source, environmental protection, aerospace, oil pipelines, solar heat collection and furnaces The main characteristics of the nano aerogel insulation felt ( fig. 1, table 1 ) are as follows:
1. superior thermal insulation performance
Due to the super thermal insulation performance of nano - pores, the total thermal conductivity of nano - aerogel insulation felt powder is less than 0.015 w / ( m k ), the total thermal conductivity of the block is less than 0.013 w / ( m k ), the total thermal conductivity of the powder under vacuum is less than 0.003 w / ( m k ), and the total thermal conductivity of the block is less than 0.007 w / ( m k ), which is one of the materials with the lowest thermal conductivity in the field of high-temperature insulation in the world at present.
2. unique flame burn-through resistance
Nano - SiO _ 2 aerogels are nonflammable and have unique flame resistance, which can withstand direct flame burning for a long time. Does not release harmful substances in high temperature or fire field, can effectively block the spread of fire at the same time, and provides more valuable time for fire escape.
3. good thermal stability
The nano si0. aerogel has a thermal stability temperature as high as 600 deg c ( porosity decrease above 700 deg c until sintered into dense si02 ), and has super hydrophobicity below 300 deg C..
4. excellent sound insulation
The nano aerogel thermal insulation felt also has the advantages of extremely low density, extremely low sound propagation speed, extremely low dielectric constant, extremely high porosity, extremely high specific surface area and the like, and is expected to become an environment-friendly high-efficiency thermal insulation and sound insulation lightweight building material with excellent thermal insulation and sound insulation performance, and has wide and great potential application value in the field of building energy conservation.
5. better light transmission
The nano aerogel thermal insulation felt also has light transmittance, can effectively transmit visible light, and can effectively block infrared radiation at the same time, therefore, the nano aerogel thermal insulation felt can be used for buildings and can well take daylighting and energy conservation into consideration.
6. good chemical stability and environmental protection
The nano aerogel thermal insulation felt mainly comprise synthetic si02, is environment-friendly and non - toxic, can resist that acid-base environment of human parts except hydrofluoric acid for a long time, doe not decompose and deteriorate, has extremely long service life under the conventional use environment, is a moisture - proof, mildew - proof, bacteria - proof, ultraviolet-resistant and overall hydrophobic material, does not cause deformation, has excellent heat insulation property and sound insulation property, and can be developed into a good completely recyclable ecological building material.