| Modern architecture is widely used large windows and luxurious glass walls,heating and cooling caused great energy consumption, and it also brings "light pollution", affect people’s lives. In recent years, more and more people began to pay attention to "green, energy saving". At present, architectural glass windows and doors,car windows to achieve the purpose of insulation and energy saving mainly through film and foil, but the effect is not ideal, their high cost and short life. The tin dioxide as representative of the new inorganic-organic composite multi-component materials are widely used in insulated glass coating. The main contents of this paper: By doping lanthanum and ytterbium to change the optical properties of tin dioxide in a different wavelength regions, expect to get both to meet the visible light transmittance, and has good barrier near infrared thermal insulation coatings.With La Cl3·7H2O, Yb(NO3)3·6H2O, and Sn Cl4·5H2O as raw material, NH3·H2O as precipitant and PEG-600 as dispersant, Lanthanum and ytterbium co-doped tin oxide nano-powder were prepared by chemical co-precipitation method. The effects of reaction temperature, reaction time, surfactant species, p H, calcination temperature and calcination time, lanthanum and ytterbium doping ratio were studied. The Lanthanum and ytterbium co-doped tin oxide powder precursors were studied by means of TG-DTA.The structure and morphology of final products were characterized by means of X-ray diffraction(XRD) and scanning electron microscopy(SEM) and other instruments.Optimized by co-precipitation of lanthanum and ytterbium co-doped tin oxide powder optimum conditions are as follows: The reaction temperature was 60℃,reaction time was 3h, the titration end point p H of nine, the doping amount of lanthanum was 0.05(molar ratio), the doping amount of ytterbium was 0.1,calcination temperature was 800℃, calcination time was 3h. Analysis of test resultsshow that lanthanum and ytterbium-doped tin dioxide was no change in phase,remains tetragonal rutile structure, spherical powder, grain size and distribution was uniform, the average particle diameter of about 40 nm, good dispersibility, only slight agglomeration.Prepared La0.05Yb0.1Sn0.85O2 slurry by mechanical grinding-ultrasonic dispersion,through sedimentation experiments discussed the impact of the dispersion medium,the type of silane coupling agents, the type and content of dispersants and other factors on the slurry stability. The results show that: when the ultrasonic dispersion time was 20 min, select deionized water as a dispersing medium, KH560 as a silane coupling agent, 3% of CTAB as dispersants, p H control at 6, prepared the best dispersion stability of the La0.05Yb0.1Sn0.85O2 slurry, the slowest sedimentation rate;settling slurry only about 4% a week; Ultrasonic treatment has big influence on the dispersibility of the slurry, the SEM and TEM results show that the nanoparticles were uniformly dispersed in slurry, uniform particle size, particle size of about 20 nm, only a relatively small agglomeration.Finally, insulation coatings were prepared by blending the water-based acrylic resin with La0.05Yb0.1Sn0.85O2 slurry, and then coated on a glass slide substrate preparation coating, and the coating was characterized UV-visible-near infrared spectroscopy and the physical properties of the coating. Discussed the influence of UV-visible near-infrared light transmittance of the doping amount of lanthanum and ytterbium, the amount of slurry and coating thickness, The results show that: when the doping ratio of lanthanum was 0.05, ytterbium doping ratio of was 0.1,slurry in an amount of 35%, and the layer thickness of three layers, the obtained coatings has the best thermal properties, the infrared blocking rate of 80%-90%, and the visible light transmittance more than 80%, reached the architectural glass coating insulating glass standard GB / T 29501-2013; coating hardness was 3H, the adhesive force was 1 level,good water resistance(immersion 24 h no foaming)... |
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