纳米空间中VO2的原位生成及阶层孔SiO2/VO2复合热致变色薄膜的制备研究

Due to the worsening of the energy crisis and environmental problem, the investigation of thermochromic VO2 thin film that undergoes a reversible and automatically regulation of optical and electrical properties without any other energy input is currently a hot research topic. However, both of the low luminous transmittance (Tlum) and the inferior solar-regulation efficiency(△Tsol and △TIR) severely restrict its commercial applications. To overcome these two drawbacks, this project proposes the study on the in-situ formation of VO2 grains in nanospace and fabrication of hierarchical porous SiO2/VO2 composite thermochromic thin films. In such a design, porous SiO2 nanoparticles can effectively reduce the refractive index of the thin film to achieve antireflective effect. More importantly, owing to the high specific surface area and spatial confinement effect of hollow cavities, mesopores, and radial holes of SiO2 nanoparticles, the contact area between SiO2 and VO2 can be significantly increased and the particle size of VO2 can be facilely controlled. Aiming at achieving a thermochromic thin film with high level of luminous transmittance(Tlum>75%), solar regulation efficiency(△TIR>25%), and stability, we will study the interfacial behavior between porous SiO2 and VO2 in depth, as well as modeling and calculating the refractive index to optimize the performance of thin films. This project could provide theoretical guidance and technical support for the practical applications of smart windows.

由于能源危机和环境问题的日益严重，不消耗其他能源就实现光热双向自动可逆调控的热致变色VO2薄膜已经成为当前的研究热点。然而可见光透过率低，太阳能调节率不高严重限制了它的实用化。本项目针对VO2热色薄膜存在的两大瓶颈问题，拟开展纳米空间中原位生成VO2晶粒及阶层多孔SiO2/VO2复合热致变色薄膜的制备研究。其中，多孔SiO2可有效降低涂层的折射率达到减反增透的效果。更重要的是，利用纳米粒子空腔、介孔和辐射状孔道的高比表面积和空间限域效应，可大大增加SiO2与VO2的接触面积并有效控制调节VO2的粒径。通过研究多孔SiO2与VO2之间的热扩散和界面行为及梯度折射率建模计算指导复合薄膜的优化设计，研制出具有高可见光透过率(Tlum>75%)、高太阳能调节率(△TIR>25%)和高稳定性的热致变色薄膜，为热色智能玻璃的实用化提供理论指导和技术支持。

VO2热致变色智能窗在不消耗其他能源的情况下可以根据外界温度变化智能地调节太阳辐射透过量，是建筑节能研究的热点。本项目基于当前VO2材料应用存在的可见光透过率低，太阳能调节率不高和节能效果差等挑战，设计并成功构筑了具有双功能的仿生凹角结构涂层(包括跳虫皮肤凹角结构、蜂巢结构以及莲蓬结构)，及超双疏可弯折的VO2/PDMS复合薄膜。通过研究多孔SiO2、图案化结构与VO2之间的界面行为及其对薄膜综合性能的影响，以及折射率建模计算指导复合薄膜的优化设计，研制出具有高可见光透过率、高太阳能调节率和高稳定性的热致变色薄膜，为热色智能玻璃的实用化提供理论指导和技术支持。此外，超双疏多功能薄膜较长的结冰延迟时间及较低的冰粘附力，显示出优异的防冰性能和稳定性。此类由简单的制备方法构筑的智能窗用柔性薄膜，突破了刚性载体的限制，拓宽了多功能智能热控制新材料的研究和应用。