| With the rapid development of modern intelligent buildings,the demand for a comfortable living environment and building energy-saving emission reduction technology have become more and more strict.Thermal insulation coatings as one of the most promising routes to alleviate the energy consumption of buildings attract extensive attention in recent years.Among them,titanium nitride materials combine the function of solar control and low-emission,being regarded as an ideal candidate for the single-layer Sun-E(solar control-low-e)energy-saving film on the glass,and the research on this is in full swing.However,the traditional method for preparing TiN films is complicated in operation,demanding in conditions and inapplicable to the preparation of energy-saving coatings on buildings with large-scale.Therefore,based on the solution film-forming method,a smooth TiN organic-inorganic composite film was prepared on the glass substrate by a simple blade coating method,and the optical performance and thermal insulation performance were studied.The research progress achieved in this paper is as follows:(1)TiN nano-powders were prepared by the sol-gel method.The effects of the type of carbon source and the sol-forming method on the synthesis products during the preparation of the precursors were studied.The results showed that polyvinyl pyrrolidone(PVP)was used as the carbon source,and the product obtained after calcination at 1300°C for 3 h had the highest purity.Among them,PVP-NHSG-TiN powder prepared by the non-hydrolytic sol-gel(NHSG)method had less agglomeration and smaller particle size.(2)Ball milling can reduce the agglomeration of TiN particles,decrease the particle size,and improve the dispersion stability of nano-powder in acrylic resin;Surface modification of TiN powder using a silane coupling agent can form an organic network coating on the surface of the powder,it will also reduce the agglomeration of particles,reduce the particle size,and improve the dispersion stability of nano-powders in acrylic resin.When TiN was modified by 20 wt.%KH570 and milled for 3 hours at1200 r/min,the composite slurry had the best dispersion stability.(3)The surface of TiN composite film prepared by doctor blade method is flat and the thickness is controllable.Moreover,the optical performance test results show that the film is selectively transmitted in the visible range and has a high reflectance in the mid-far infrared,which meets the requirements of the Sun-E film.Combined with the results of the simulated thermal insulation test,it is shown that the TiN composite film can be used as a single-layer thermal insulation film in architectural window glass.In addition,as a Sun-E film,the PVP-NHSG-TiN film with a smaller particle size has better optical performance than the PVP-HSG-TiN film.The transmittance at the peak of 471nm is 35.28%,and the average reflectance of the middle and far infrared is 52.34%;Correspondingly,it also shows better thermal insulation performance.After60 minutes of infrared irradiation,the indoor temperature increased by 21°C,which was 6.4°C lower than ordinary glass;After 40 minutes of natural cooling,the indoor temperature decreased by 19.2°C,which was 7.2°C lower than ordinary glass.(4)Incorporation of urea in the preparation of the precursor can increase the nitrogen content in the synthesized product TiN_x,the ratios of nitrogen atoms to titanium atoms in the samples N-HSG-TiN and N-NHSG-TiN are 0.97 and 0.98,respectively,which are close to the standard stoichiometric ratio.In addition,compared with the TiN film,the transmittance of the TiN_x composite film in the visible light region is increased,and the transmission peak is red-shifted from 471nm to 503nm,while the optical properties in other wavelength bands have not changed significantly.It shows that increasing the nitrogen content of titanium nitride can enhance the indoor lighting performance of the composite film while maintaining good thermal insulation performance. |
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