Research On Preparation And Solar Reflection Spectrum Of Doped Sodium Zincophosphate

High reflective dark materials of doped sodium zincophosphate were prepared by heat-treating precursor with zinc sulfate, phosphoric acid, anhydrous sodium carbonate as main starting materials and cupric nitrate, ferric nitrate, nickel sulfate as dopants via coprecipitation method. The effects of synthesis process, doping amount and heat-treatment temperature on crystal structure, color, particle size, morphology, infrared emissivity and solar reflection of the product were analysised by XRD?TG/DSC?SEM and UV-VIS-NIR spectrophotometer, etc. Besides, the thermal reflective coatings were prepared with the high reflective material of copper doped sodium zincophosphate as pigment, the performance of heat insulation was tested as well. The results of research show that:The optimum preparation parameters of copper doped sodium zincophosphate were temperature of oil bath at 70?, two steps reaction time for 0.5h and 1h, reactant concentration at 1mol/L, ratio of phosphoric acid P/?Cu+Zn? at 0.5, p H of solution at 9. The powder was black in the visible light band, and had an excellent reflective property in the near infrared band after heat-treating at 700?. The reflection properties of the product firstly increased and then decreased with the increase of the doping amount after heat treatment at 600?. The highest near-infrared reflectance was 57.4% when the doping content was 0.5. The near-infrared reflectance of NaZn_0.5Cu_0.5PO₄ gradually increased with the rise of heat treatment temperature, and the highest reflection was reached at 60.4% after heat-treating at 700?.Red thermal reflective materials were prepared by iron doped sodium zincophosphate, its color was deepened from orange red to deep red with the increase of the doping amount. Lattice distortion was intensified by doping, as well as the particles melting, and defects increasing were attributed to over-firing, which led to the decrease of reflection properties in the near infrared band of the product. The product NaZn_0.9Fe_0.1PO₄ had the highest reflection of 68.4% after heat treatment at 600?.Gray heat reflective materials were prepared by nickel doped sodium zincophosphate, its reflection properties decreased with the increase of the doping amount after heating at 600?. The product NaZn_0.9Ni_0.1PO₄ had the highest reflection of 55.7% after heat-treatment at 600?. With the rising heat treatment temperature, the color of NaZn_0.9Ni_0.1PO₄ was deepened and the reflectivity decreased. the product NaZn_0.9Ni_0.1PO₄ presented the highest reflection of 59.0% after heat treatment at 400?.Thermal reflective coatings were prepared with acrylic resin as the film, NaZn_0.5Cu_0.5PO₄ as the pigment, which had the excellent thermal insulation performance. With the increase of coating thickness, the reflective performance was improved rapidly, until a certain thickness, and then the improvement in reflection was gradually slowed down. The insulation effect of NaZn_0.5Cu_0.5PO₄ heat reflective coating was much better, the back temperature of coated plate was 10? lower than that of carbon black coating, 28.4? lower than that of Shi Zhan Black coating.Materials of a variety of colors with high near-infrared reflectance can be prepared by three kinds of transition metal elements dope zinc phosphate sodium, which contains copper, iron and nickel in present thesis. By using them as pigment in the coating, the effect of heat insulation and cooling of coating can be obviously improved.