Study On Near Infrared Barrier Technology Of Transparent Materials

In summer,in order to mitigate the high temperature in the greenhouse,researchers usually add NIR barrier agent in the substrate to reduce the indoor ambient temperature.In this paper,the barrier agents with near-infrared reflection and near infrared absorption are prepared by.hydrothermal method,and a composite insulating film is prepared by hydrothermal method.The main work is as follows:1.The nanoscale nano powder was prepared,and the citric acid solution concentration was 0.050 moL/L,the reaction time was pH=1 and the reaction time was 6 h.The prepared microspheres were composed of bismuth oxychloride,with a strong near infrared reflectance,and the average reflectance of near red outside was 99.88%.When the amount of BiOCl is 1.5%,the BiOCl/PVA composite membrane can reduce the ambient temperature in the heat insulation box by 3.0 °C.BiOCl/PVA composite film has good ability to block solar heat.2.With aluminum as the doping source and the doping amount of 0.006 moL,the reaction time is pH=1 and the reaction time is 6 h.The obtained Al-CuS powder has a strong near infrared absorption capacity,the band gap of the powder is 1.74 eV,and the average transmittance of the near infrared region of 750-2500 nm is 43%.Meanwhile,in the visible range of 300-750 nm,the average transmittance is as high as 67%.When the addition of Al-CuS is 2.5 wt%,the average transmittance of the Al-CuS/PVA composite film in the near infrared is only 16%,while the average ejection rate in the visible region is kept at 50%.The composite film can reduce the ambient temperature in the heat insulation box by 3.6 ?.It can be seen that the Al-CuS/PVA composite film with near infrared absorption has good performance of blocking solar heat.3.when the Al-CuS/phthalocyanine blue(BGS)=1.0/1.5,the blue shift of transmission spectrum is obvious,and the maximum transmittance is 68.1%.When the addition of BGS:Al-CuS is 2.50 wt%,the average transmittance of the BGS:Al-CuS/PVA composite film in the near infrared region is 21.4%,and the maximum transmittance of the visible light is 52.1%.4.with the addition of Al-CuS into EVA film,the tensile strength and elongation at break gradually follow a downward trend.The average transmittance in the near infrared region is reduced to 10.04%,and the average transmittance in the visible region is gradually reduced to 47.23%,and the Al-CuS/EVA insulation film can reduce the ambient temperature of the heat insulation box by 3.5 °C.With the increase in the content of the BGS:Al-CuS composite powder in the EVA film,the elongation at break and the tensile strength increase first and then decrease.The trend.The average transmittance in the near infrared region is gradually reduced to 25.6%,and the maximum transmittance in the visible region is gradually reduced to 49.1%,and the BGS:Al-CuS/EVA insulation film can reduce the ambient temperature in the heat insulation box by 3.8 ?.