Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, Liaoning 110819, China.
Nanoscale. 2019 Feb 7;11(6):2795-2804. doi: 10.1039/c8nr08900k.
Optical sensors of temperature possess the unique advantages of contactless measurement and large-scale imaging. Developments have been rapidly made in optical fiber sensors due to their high sensitivity, short response time, and electromagnetic immunity, and being easy to handle and light weight. Therefore, novel optical sensors of temperature based on optical fibers were fabricated to explore their application in special environments, such as poisonous, sparkless, currentless, and gelid ones. The present study is the first report of successful intercalation of neutral Y(iii) complexes in situ into the gallery of Y/Eu binary layered rare-earth hydroxides by hydrothermal processing without replacing the nitrate ions. The swollen layered rare-earth hydroxides were then exfoliated into ultrathin nanosheets ∼2 nm thick through dispersion in formamide. Grafting of Tb(iii) complexes onto the exfoliated nanosheets yielded novel temperature sensor films <100 nm thick, which exhibited color emissions from green to pink tunable through temperatures ranging from 77 to 360 K under ultraviolet excitation. Due to the highly sensitive and temperature-dependent emission, an optical fiber-based temperature sensor was fabricated by employing these novel allochroic films, which showed luminescence that could reversibly undergo repeated thermocycles. These optical fiber sensors have the potential to open up new fields in material functionalities via nanostructure manipulation and functionalized optical fiber engineering.
光学温度传感器具有非接触式测量和大规模成像的独特优势。由于光纤传感器具有高灵敏度、短响应时间、抗电磁干扰以及易于处理和重量轻等优点，因此得到了迅速发展。因此，基于光纤的新型光学温度传感器被制造出来，以探索其在特殊环境中的应用，如有毒、无火花、无电流和冰冷环境。本研究首次报道了通过水热处理成功地将中性 Y(iii)配合物原位嵌入 Y/Eu 二元层状稀土氢氧化物的层间，而不取代硝酸盐离子。然后，通过在甲酰胺中分散，溶胀的层状稀土氢氧化物被剥离成厚度约为 2nm 的超薄纳米片。Tb(iii)配合物接枝到剥离的纳米片上，得到了厚度<100nm 的新型温度传感器薄膜，在紫外光激发下，其发射颜色可在 77 至 360K 的温度范围内从绿色调谐到粉红色。由于具有高灵敏度和温度依赖性的发射，通过采用这些新型变色薄膜制造了一种基于光纤的温度传感器，其发光可在热循环中可逆地重复进行。这些光纤传感器通过纳米结构操纵和功能化光纤工程，有可能在材料功能方面开辟新的领域。
