热致变色智能薄膜辐射特性及其控制方法研究

The objectives of this program are to investigate thermal radiative properties and its control method of Thermochromic Smart Film (TSF) from (a) adjusting phase transition width (PTW) of Thermochromic Smart Material (TSM), which used to prepare TSF, so as to the phase transition to occur in a narrow room temperature range, and discussing the relationship of PTW dependence of doping level and ion radius, (b) measuring thermal radiative properties of TSF and analyzing some key influence factors to explore the mechanism of emissivity variation,(c) unraveling the mechanism of microstructure dependence of thermal radiative properties of TSF, and (d) developing control method of thermal radiative properties of TSF. When TSF used in spacecraft thermal control, one expect a sharp emissivity increase to occur in a narrow room temperature range upon heating. There is emerging evidence suggesting that PTW can be adjusted by different ion radius, although the underlying mechanism is unclear, which this program seeks to explore. For example, resistivity is caused by a sudden increase in a certain ion radius resulting in PTW variation. The research will be conducted by preparing some samples with different doping element and doping level, and by testing their resistivity and magnetization to reveal the relationship of PTW dependence of ion radius. The variation law of thermal radiative properties of TSF is also unclear, which will be explored in this research. Preparation of TSF will be conducted by optimizing key parameters to study its thermal radiative properties and unravel its variation mechanism with temperature. This program will seek to improve the thermal radiative properties of TSF, which is motivated by previous work on micro-scale radiative energy transmission. This work suggested that thermal radiative properties can be controlled by designing suitable microstructure, which size is less than or equal to characteristic wavelength of thermal radiation. The valuable work will be performed in this research and the mechanism of emissivity enhancement will be clarified. In order to overcome the drawback of high solar absorptivity of TSF, microstructure is designed to improve TSF's thermal radiative properties. Radiative properties based on the structure is investigated by solving transmission matrix of multilayer microsturcture. It is expected that these key questions in thermal control application of lightweight TSF device can be solved by this work’s execution. Research will be meaningful to enrich the contents of thermal radiation theory and to enhance thermal control performance of system and equipment. It is also possible to promote the development of space micromation technology.

针对微小型航天器热控技术发展的需求开展热致变色智能薄膜(TSF)辐射特性及其控制方法研究。研究室温窄区内TSF相变温度的调控方法，分析退火温度、气氛、应变对TSF相变特性的影响，揭示其相变温度的变化规律。研究TSF的制备方法，实验测试其辐射特性，分析薄膜工艺、膜厚、基底材料种类、应变及退火效应对TSF的作用机制，揭示其辐射特性的转变规律。理论研究微结构耦合TSF热辐射特性及机理，探索TSF辐射特性的调控方法，优化设计辐射特性调控微结构，分析微结构尺寸参数、形状、周期性等对其辐射特性的影响,揭示其辐射特性的调控机理。实验研究微结构耦合TSF辐射特性，探索轻量型TSF热控器件的研制方法。该项目对于丰富热辐射理论与方法的研究内涵，提高系统与设备的热控水平具有重要意义。同时也为我国空间微型化技术发展奠定基础。

随着新需求的不断涌现，未来空间平台除了要求轻量化、微型化、多功能性外，还要具备在轨机动、智能自主、目标识别、跟踪与防御等能力。当平台载荷进行大的轨道机动时，热控系统要能在剧烈变化的热环境中对载荷的瞬时温度波动进行智能反馈调节。而传统的以被动热控为主、主动电加热为辅的热控技术由于电功率需求过大、对载荷姿态和工作模式要求苛刻、主动调节能力不足等原因，已成为制约未来高性能空间载荷研制的关键瓶颈技术。.项目以空间载荷智能自主热控需求为背景，开展了掺杂热致变色智能薄膜，图案化微栅/微腔热致变色智能薄膜，以及基于高分子材料的柔性热致变色智能薄膜等的设计、制备、及其辐射特性调控与优化研究。通过单价K掺杂，成功制备了纳米尺度厚热致变色薄膜，更正了传统认为的只有薄膜达到微米厚才能实现热致变色特性的认知缺陷。创新地提出了异质结热致变色薄膜辐射特性的调控方法，实现了热致变色薄膜辐射特性的低温区有效调控。提出了微栅/微腔结构的热致变色薄膜表面结构，揭示了微结构与热致变色薄膜辐射特性的作用机制。创新性的提出了高分散性的热致变色纳米粒子前驱体溶剂热诱导熔盐法，将纳米粒子的粒径控制在30nm以下。发展了聚酰亚胺的原位聚合方法，设计了新的含氟基团分子链结构，研制了耐紫外辐照、耐320℃高温、低吸辐比、且无色透明的聚酰亚胺薄膜，并在此基础上，成功制备了聚酰亚胺柔性热致变色薄膜，涂层发射率调控幅度达到0.45。本项目所开展的研究从理论和实验两方面系统地揭示了材料属性、结构、制备工艺等对热致变色薄膜辐射特性的调控机理，解决了发射率调控幅度低，太阳吸收率高的基础难题。.本项目已发表SCI学术论文6篇，EI学术论文2篇，授权发明专利2项，申请发明专利3项，参加国际学术交流2次，国内学术会议3次。培养硕士研究生3人。