聚合物分散液晶(PDLC)是一种液晶以微滴形状分散在连续聚合物基体中的复合薄膜。在零场条件下，液晶分子无规取向，由于液晶微滴与聚合物基体之间的折射率不同，薄膜呈现不透明状态。当施加外部电场时，液晶分子重新排列与电场力方向一致，此时聚合物与液晶微滴折射率相匹配，薄膜呈现透明状态。与传统的电致变色和热致变色智能窗相比，PDLC在光学领域具有广阔的应用前景。然而，它们的应用受到一些缺点的限制，比如高驱动电压、低对比度和热稳定性差，尤其是高工作电压，是研究人员一直在努力解决的问题。

  近日，北京科技大学杨槐/于美娜团队等人通过将高清亮点液晶单体引入PDLC体系中，开发设计了一种可在较高温度下仍保持着低电压、高对比度和快速响应的PDLC薄膜。该薄膜在智能显示领域和智能窗领域有着良好的应用前景。相关工作以“An intelligent electrochromic film with passive radiative cooling and synergistic solar light control capabilities for display and smart windows”为题发表于Journal of materials chemistry A, 北京科技大学/北京大学杨槐教授、于美娜副研究员、王茜特聘副研究员为共同通讯作者，北京科技大学新材料技术研究院博士生张作为为文章第一作者。

Figure 1. Schematic diagram of the preparing process and working mechanism of PDLC film.

Fig 3. (a-f) Reflection notch dispersion image of the five samples recorded at different temperatures, in which the transmittance is represented by the color; (g-i) (g) The V_sat; (h) CR; and (i) Response time of B3 sample at different temperatures.

Fig 4. (a-b) Patterned PDLC based on different CRs in the on and off states; (c-d) Mechanism of the image-imbedded PDLC displays with the demonstrated photo images of word “B” and “Four-leaf clover” at several driving voltages; (e) transmittance images of the film at different voltages; (f) UV-Vis-NIR spectra at different voltages (g) reflection spectra of film at off-state and on-state; (h) the response time curve (sample B3); (i) the transmittance of the spectra of the initial film and the film after 100 cycles;

Fig 5. (a) Solar transmittance and infrared emissivity curves; (b) Absorbance spectrum of PDLC film with ATR-FTIR spectroscopy; (c) the temperature variation of the films under simulated sun light; (d) Temperature of thin film under different voltages; (e) calculated net cooling power during the nighttime of PDLC film; (f) calculated net cooling power during the daytime of PDLC film; (g) variation of integral luminous transmittance in 380-780 nm (T_lum) and solar transmittance in 380-2500 nm (T_sol) under different voltages; (h) Response time and ΔT_lum of PDLC film and EC switchable materials to compare their dynamic modulation capability.

  原文链接：https://doi.org/10.1039/d4ta04621h