Glass heat insulation coating is a coating prepared by processing one or several nano-powder materials. The nano-materials used have special optical properties, that is, they have a high barrier rate in the infrared and ultraviolet regions, and a high transmittance in the visible light region. Using the transparent heat insulation properties of the material, it is mixed with environmentally-friendly high-performance resins, and processed by a special processing technology to prepare energy-saving and environmentally-friendly heat-insulating coatings. Under the premise of not affecting the glass lighting, it achieved effect of energy saving and cooling in summer, and energy saving and heat preservation in winter.
In recent years, exploring new types of environmentally friendly thermal insulation materials has always been the goal pursued by researchers. These materials have very broad application prospects in the fields of green building energy saving and automobile glass heat insulation-nano powder and functional film materials that have high visible light transmittance and can effectively absorb or reflect near-infrared light. Here we mainly introduce cesium tungsten bronze nanoparticles.
According to relevant documents, transparent conductive films such as indium tin oxide (ITOs) and antimony-doped tin oxide (ATOs) films have been used in transparent heat insulation materials, but they can only block near-infrared light with wavelengths greater than 1500nm. Cesium tungsten bronze (CsxWO3, 0＜x＜1) has high visible light transmittance and can strongly absorb light with wavelengths greater than 1100nm. That is to say, compared with ATOs and ITOs, cesium tungsten bronze has a blue shift in its near-infrared absorption peak, so it has attracted more and more attention.
Cesium tungsten bronze nanoparticles have a high concentration of free carriers and unique optical properties. They have a high transmittance in the visible light region and a strong shielding effect in the near-infrared region. In other words, cesium tungsten bronze materials, such as cesium tungsten bronze transparent heat-insulating coatings, can ensure good visible light transmittance (without affecting lighting) and can shield most of the heat brought by near-infrared light. The absorption coefficient α of a large number of free carriers in the cesium tungsten bronze system is proportional to the free carrier concentration and the square of the wavelength of the absorbed light, so when the cesium content in CsxWO3 increases, the concentration of free carriers in the system gradually increase, the absorption enhancement in the near-infrared region is more obvious. In other words, the near-infrared shielding performance of cesium tungsten bronze increases as its cesium content increases.