Preparation And Properties Of AZO/Cu/AZO/X/PET Thermal Insulation Film

AZO（Al doped ZnO）transparent conductive films have been favored by researchers due to their excellent photoelectric properties and abundant resources.In order to further improve the photoelectric properties of AZO thin films,many researchers have introduced metal layers in the middle of AZO thin films to form sandwich structure films.It is found that the AZO/Cu/AZO film has very low surface resistance,infrared emissivity and high visible light transmittance,and has the potential to be a transparent solar barrier film.In view of this,multilayer films were prepared by magnetron sputtering.The effects of SiO₂and CTO layers on the crystallization properties,surface morphology,photoelectric properties and infrared emissivity of AZO/Cu/AZO films were studied.In order to make the film to be closer to the actual application requirements,the wear-resistant layer of AZO/Cu/AZO/X/PET film was prepared by coating method,and the wear-resistant coating with high transparency and high wear resistance was prepared.It lays a foundation for the application of AZO/Cu/AZO/X multilayer films as building insulation films.The specific research results are as follows:AZO/Cu/AZO/SiO₂thin films with different SiO₂layer thicknesses were prepared on glass and PET substrates,respectively.The effects of different substrates and different SiO₂layer thicknesses on the crystallization properties,photoelectric properties and infrared emissivity of AZO/Cu/AZO/SiO₂thin films were systematically studied.Appropriate SiO₂thickness can improve the infrared performance of the film while ensuring high visible light transmittance.When the substrate is glass,the SiO₂layer thickness of 36 nm film has the best comprehensive performance.At this time,the visible light transmittance is 81.2%,the maximum near-infrared barrier is 60.0%,the square resistance is 8.37 Ohm/square,and the infrared emission rate is 0.048.When the substrate is PET and the thickness of SiO₂layer is 9 nm,the visible light transmittance is 74.0%,the maximum near-infrared barrier is 64.0%,the square resistance is 8.1Ohm/square,and the infrared emissivity is 0.149.In order to improve the ultraviolet performance of AZO/Cu/AZO/X films,AZO/Cu/AZO/CTO films with different CTO layer thicknesses were prepared on PET substrates.Appropriate CTO layer thickness can promote grain size to grow.As a result,the band gap of AZO/Cu/AZO/CTO film is narrowed,the absorption edge is red-shifted,the ultraviolet barrier rate is greatly improved,and the infrared barrier rate is slightly increased.It is found that the change trend of infrared emissivity with square resistance follows the second-order function.The CTO layer can improve the reverse bending performance of AZO/Cu/AZO/CTO film and reduce the forward bending performance.When the CTO film is 34.2 nm,the film has the best comprehensive performance.At this time,the UV blocking rate is 92.0%,the near-infrared blocking rate is 46.5%,the visible light transmittance is 62.5%,and the 8-14μm infrared emissivity is 0.163.In addition,in order to meet the requirements of practical application,a wear-resistant coating was prepared.The UV-curable coating mainly achieved three-dimensional polymerization through cross-linking reaction to form a network structure with certain strength.Its composition has a crucial influence on the performance of the coating.By adjusting the ratio of oligomers and monomers in the coating,the content of additives,the ratio and content of photoinitiators,the wear resistance,hardness and optical properties of the samples were studied.It was found that the proportion of oligomers was between 70%and 72.5%,the proportion of monomers was between 27.5%and 30%,the content of additives was between 12.5%and 15%,the ratio of photoinitiators was 3:7,and the content was 5%～6%.The comprehensive mechanical and optical properties of wear resistance are optimal.