Sandia National Laboratories , Livermore , California 94551-0969 , United States.
ACS Appl Mater Interfaces. 2018 Jul 18;10(28):24201-24208. doi: 10.1021/acsami.8b07377. Epub 2018 Jul 6.
Because of their extraordinary surface areas and tailorable porosity, metal-organic frameworks (MOFs) have the potential to be excellent sensors of gas-phase analytes. MOFs with open metal sites are particularly attractive for detecting Lewis basic atmospheric analytes, such as water. Here, we demonstrate that thin films of the MOF HKUST-1 can be used to quantitatively determine the relative humidity (RH) of air using a colorimetric approach. HKUST-1 thin films are spin-coated onto rigid or flexible substrates and are shown to quantitatively determine the RH within the range of 0.1-5% RH by either visual observation or a straightforward optical reflectivity measurement. At high humidity (>10% RH), a polymer/MOF bilayer is used to slow the transport of HO to the MOF film, enabling quantitative determination of RH using time as the distinguishing metric. Finally, the sensor is combined with an inexpensive light-emitting diode light source and Si photodiode detector to demonstrate a quantitative humidity detector for low humidity environments.
由于具有极高的比表面积和可调节的孔隙率，金属-有机骨架（MOF）有望成为气相分析物的优秀传感器。具有开放金属位点的 MOF 特别适合检测路易斯碱性大气分析物，例如水。在这里，我们证明可以使用 MOF HKUST-1 的薄膜通过比色法来定量测定空气的相对湿度（RH）。HKUST-1 薄膜旋涂在刚性或柔性基底上，并通过目视观察或简单的光反射率测量，在 0.1-5% RH 的范围内定量测定 RH。在高湿度（>10% RH）下，使用聚合物/ MOF 双层来减缓 HO 向 MOF 薄膜的传输，从而可以使用时间作为区分度量来定量测定 RH。最后，将传感器与廉价的发光二极管光源和 Si 光电二极管检测器结合，展示了一种用于低湿度环境的定量湿度检测器。
