基于柔性热控智能多孔节能膜的隔热保温机制研究

Thermochromic window of vanadium dioxide (VO2) is an important way to reduce the energy consumption of the buildings. It has active response to the change of the environmental temperature by the intelligent controllable way of heat transfer on absorption/blocking the sun's heat, which can achieve two-way intelligent control of adiabatic and heat preservation. Therefore, the flexible film made by VO2 has become one of the most effective way to achieve the energy conservation of the building glass, which has wide application prospect and excellent social and economic value. However, the heat insulation performance of this flexible film of the VO2 is poor, and lack of system to study the mechanism of this problem. So the project, "The research on heat insulation mechanism of the thermal controllable intelligent energy-saving film with the porous structure", is proposed as the subject. The relationship between VO2 crystal structure and thermal properties will be analyzed. The mutual effect between the composition, microstructure of the flexible thermal control intelligent energy-saving VO2 film and sunlight reflection, absorption and transmission will be explored. The interaction of regularity of the flexible thermal control intelligent energy-saving film and the two-way radiation adjustment process will be studied. Then, the influencing factors of the thermal conductivity of thermal control intelligent energy-saving film will be summarized, which the VO2 film initiative to adapt to changes in temperature and sunlight radiation and heat conduction can be grasped. Moreover, the heat insulation mechanism of flexible thermal controllable intelligent energy-saving film. Therefore, the results of thermal insulation would lay the foundation for the application of thermal controllable smart nanocomposites system in intelligent energy-saving system in the coming future.

二氧化钒(VO2)热致变色窗是降低建筑降耗的重要方法，具有主动响应环境温度变化的智能吸收/阻隔太阳热的传热方式，能实现隔热保温的双向智能调控。VO2柔性贴膜已成为解决建筑玻璃高能耗问题的最有效途径之一，具有广泛的应用前景和优异的社会经济价值。本申请针对VO2薄膜隔热保温性能较差、系统研究其机制缺乏等问题，以“基于柔性热控智能多孔节能膜的隔热保温机制研究”为课题，通过分析VO2晶体结构与其光热性能的关系，研究VO2柔性热控智能节能膜组成、微结构与太阳光反射和透过的相互作用规律，探究VO2柔性热控智能节能膜与热传导、辐射双向调节过程，总结柔性热控智能节能膜导热系数的影响因素，掌握VO2薄膜主动适应环境温度变化与太阳光热量辐射、传导的规律，建立柔性热控智能节能膜的隔热保温机制，为热控机敏纳米复合体系在下一代智能节能系统中的应用提供技术支撑和理论依据。

VO2热致变色窗具有主动响应环境温度变化，实现隔热保温的双向智能调控可有效降低降耗。本项目研制出系列掺杂/共掺杂不同形貌的VO2微纳米颗粒，采用旋涂沉积、核壳包覆、仿生设计等多种手段构建柔性膜表面微结构，研究发现：Mg/W共掺杂、自助装微纳团簇VO2，相变潜热达43.2 J/g，其使得柔性热控膜光学性能获得较大改善（Tlum=49%，ΔTsol=8.1%）；表面调控后的柔性膜获得较好的光热性能（Tlum=61%，ΔTsol=10.5%；ε20℃=0.21，ε90℃=0.62，Δε=0.41；28.5 mW/mK的低热导率）；隔热保温性能主要是由于VO2的热致变色产生，其实现归因于VO2(M/R)的可逆晶体相变，并引起显着的光学性质变化，而VO2(M/R)微纳结构可通过将与温度相关的透射率对比转移到具有密集能量的太阳光谱上来增强太阳能调制。可见，该膜对热量的调节主要依赖于VO2(M/R)在近红外范围内的主动局部表面等离子体共振（LSPR）机制，并通过Lumerical FDTD Solutions 进行三维有限差分时域 (3D-FDTD) 模拟得到进一步验证。. 本项目研究可提供一种柔性、可粘贴的控温膜，可为智能窗温度调节（0.38~2.5μm）提供可行方案。随着人口和经济活动的增长，在世界较热的地区，建筑物中的空调使用量有望激增，进一步增加世界能源消耗和CO2排放。幸运的是，辐射冷却可提供被动、负担得起且更高效的冷却解决方案，并在不排放任何CO2的情况下满足空间冷却能源需求，它依赖于地球物体通过IR向寒冷(3 K)外层空间的红外(IR)辐射自然发射-大气的透明窗口（8~13 μm），有望减少与供暖和制冷相关的碳排放，提高建筑物的可持续性。因此，随着碳达峰碳中和战略实施，有必要进一步研究被动辐射冷却调节功能的VO2基热致变色智能窗。. 此外，在本项目资助之下，课题组进行了拓展研究，包括：时间温度指示剂、食品新鲜度指示剂、用于小分子气体敏感的传感器等。在本项目支持下，共计发表15篇科技论文（本资助基金为第一标注），其中SCI收录11篇，二区以上11篇，中文科技论文4篇，授权专利2项；共计参加国内外学术会议、讲座共计10次，其中境外2次；支持了9名研究生开展相关研究工作。. 综上，本项目完成了预期目标。