Inorganic Chemistry I, Technische Universität Dresden , Bergstraße 66, 01062 Dresden, Germany.
ACS Appl Mater Interfaces. 2017 Dec 20;9(50):43782-43789. doi: 10.1021/acsami.7b13924. Epub 2017 Dec 7.
Switchable metal-organic frameworks (MOFs) showing pronounced and stepwise volume changes as a response toward external stimuli such as partial pressure changes were integrated into electron conductive composites to generate novel threshold sensors with pronounced resistivity changes when approaching a critical partial pressure. Two "gate pressure" MOFs (DUT-8(Ni), DUT = Dresden University of Technology, and ELM-11, ELM = Elastic Layer-structured MOF) and one "breathing" MOF (MIL-53(Al), MIL = Material Institute Lavoisier) are shown to cover a wide range of detectable gas concentrations (∼20-80%) using this concept. The highest resistance change is observed for composites containing a percolating carbon nanoparticle network (slightly above the percolation threshold concentration). The volume change of the MOF particles disrupts the percolating network, resulting in a colossal resistance change up to 7500%. Repeated threshold detection is particularly feasible using MIL-53(Al) due to its high mechanical and chemical stability, even enabling application of the composite sensor concept in ambient environment for the detection of volatile organic compounds at high concentration levels.
可切换的金属有机骨架（MOFs）在对外界刺激（如分压变化）的响应中表现出明显的逐步体积变化，将其集成到电子导电复合材料中，可生成新型的门限传感器，当接近临界分压时，其电阻会发生明显变化。两种“门限压力”MOFs（DUT-8（Ni）和 ELM-11，DUT = 德累斯顿工业大学，ELM = 弹性层结构 MOF）和一种“呼吸”MOF（MIL-53（Al），MIL = 材料研究所拉瓦锡）被证明可以使用这种概念覆盖广泛的可检测气体浓度范围（约 20-80%）。对于含有渗透碳纳米粒子网络的复合材料（略高于渗透阈值浓度），观察到最高的电阻变化。MOF 粒子的体积变化会破坏渗透网络，导致高达 7500%的巨大电阻变化。由于 MIL-53（Al）具有较高的机械和化学稳定性，重复的门限检测特别可行，甚至可以使复合传感器概念应用于环境中，以检测高浓度水平的挥发性有机化合物。
