新型太阳光驱动的冷/暖色调可调智能窗薄膜的制备及其性能研究

VO2是一种热致变色材料，能够根据环境温度变化对进入室内的太阳辐射能量进行调控，在智能窗领域具有非常广阔的应用前景。目前，基于VO2的智能窗已取得较大进展，但在实际应用中仍存在两方面挑战：一是用于刺激VO2光学性能变化的外加装置将增加智能窗的结构复杂性和能量消耗；二是无法实现智能窗冷/暖色调的转换而满足人类对色调舒适性的需求，并且对太阳能量调节能力较弱。针对上述挑战，拟通过以下研究进行解决：一是利用金属纳米粒子的高效光热转换效应，将太阳能转换为热能，驱动VO2的透过率发生变化，实现智能窗冬暖夏凉的目的，并且金属纳米粒子与VO2复合后，其红外发射率降低，能增加智能窗的保温性；二是结合VO2在近红外波段和热致变色微胶囊在可见光波段的太阳能调制协同效应，实现双波段调控，大幅提高复合薄膜的节能效率，同时实现冷/暖色调可转换功能。在此基础上进一步探索复合薄膜的服役性能，为智能窗的应用推广奠定基础。

VO2 is one kind of thermochromic materials, which can intelligently control the amount of solar radiation in accordance with the temperature variations. Such characteristic makes VO2 a potential material for the energy-efficient smart windows. To date, VO2-based smart windows have made great progress, but practical applications still remain restricted by two tough challenges. The first challenge is that additional power or heating devices are needed for optical switching of VO2, but these devices will increase the complexity of system’s structure and consume energy. The second challenge is that VO2-based smart window systems are limited to a regulation of solar energy input, but cannot realize the conversion of warm/cold-tone to improve the emotions of people. Moreover, it is accompanied by small solar modulation efficiency. In view of the above two challenges, this project intends to adopt two strategies. (1) Owing to the high photothermal conversion effect of metal nanocrystals, the infrared switching behavior of VO2-based smart windows can be triggered by sunlight irradiation to keep the building cool in the summer, and warm in the winter. In addition, the composite films composed of VO2 and metal nanoparticles can decrease the infrared emissivity to increase the thermal insulation of smart windows. (2) The high solar modulation efficiency is attributed to the modulation of thermochromic microcapsule in visible light waveband as well as VO2 in near infrared region. Meanwhile the warm/cool tone-switchability can be realized. Furthermore, the service performance of the composite films will be characterized, which can lay a good foundation for the practical application of smart windows.