Preparation And Performance Of Glass-Based Thermochromic Thermal Insulation Coatings

According to the statistics,the energy consumed by refrigeration of air conditioners in summer accounts for about 50%of the total energy consumption of buildings owing to entry into indoor space of much heat from the sunlight via the glasses of doors and window.Therefore,in recent years,the development of thermochromic heat-insulating glass that can intelligently control near-infrared and visible light,adjust indoor temperature and brightness has become one of the research hotspots.However,the currently-reported thermochromic smart glasses confront such problems as complex glass structure,poor stability of key materials,unsatisfactory thermal insulation,small range of light adjustment and uncomfortable colors,which seriously restricts its practical application.In this work,for the first time,a novel[（C₂H₅）₂NH₂]₂NiCl₄ thermochromic organometallic complex synthesized by an one-step,eco-friendly and efficient solid-phase mechanochemical route was applied to a glass-based coating to successfully achieve the stable thermochromic effect in a glass-based coating,and nano cesium tungsten bronze（CWO）and nano tin antimony oxide（ATO）with super absorption capacity in different near-infrared bands were further introduced into the coating to obtain stable high-performance thermochromic heat-insulating coating.In this thesis,the influence of the composition ratio of thermochromic complexes and nano functional powders on the optical and thermochromic properties of coatings was systematically studied,and the optimal coating formulation and process were obtained.Then the thermal insulation property and stability of thermochromic heat-insulating coated glass were investigated,its energy-saving effect was evaluated by energy consumption simulation and actual energy-saving tests,and finally the energy-saving mechanism was discussed.The results are as follows:（1）the phase transition temperature of[（C₂H₅）₂NH₂]₂NiCl₄ glass-based coating can realize a stable reversible color evolution from transparent to blue at the more suitable temperature of 46.3℃,and the adjustment ability of the coating to visible light can be enhanced with the increase of the amount of complex.（2）The heat-insulating and energy-saving effect of the intelligent glass with composite coating of thermochromic[（C₂H₅）₂NH₂]₂NiCl₄ and thermal insulation CWO-ATO（CA）materials is superior to that of the glass with coating of only CWO.In the case of 3.8wt%addition of the complex,5.83wt%respective addition of CWO and ATO,the Ni-Cl-CA composite glass coating with 10.50μm in thickness possesses 70%visible light transmittance,27%visible light adjustment ability and 90.7%near-infrared shielding ability.（3）The composite coating of Ni-Cl-CA smart glass exhibits excellent thermochromic stability and weather resistance.Energy Plus energy consumption simulation shows the energy saving rates of Ni-Cl-CA smart glass in four cities of Ganzhou,Bangkok,Kuwait and Phoenix are 11.1%,8.9%,11.02%and 15.21%,respectively.The obtained energy-saving data also demonstrates that the Ni-Cl-CA composite coating smart glass can reduce the indoor temperature by 16.1℃ and 10.9℃,respectively compared with bare glass and CA coating glass,which confirms that that composite coated glass with thermochromic materials and thermal insulation materials can produce better energy saving effects.In short,based on thermochromic complexes,the single-coated glass with the intelligent heat-insulating and thermochromic functions was fabricated for the first time,showing superior energy-saving effects,which provides a novel and facile route for the preparation of intelligent energy-saving coated glass and promise of broad application prospects.