Dielectric and Ferroelectric Surface-Mounted Metal-Organic Frameworks (SURMOFs) as Sensor Devices

可调性、孔隙度和构象柔韧性是金属有机骨架（MOFs）的关键性能。这类材料的一个新兴应用领域是它们在高度小型化的传感器结构中的应用。该项目的主要目标是开发一种新型传感器概念，直至概念验证阶段。通过对纳米颗粒金属（NGM）传感层电导率的相关调制，可以检测表面安装的mof （surmof）中分析物客体分子的吸附，从而导致其介电性能的变化。该传感层是SURMOF/NGM异质结构的一部分。ngm是包含嵌入在非导电基体中的金属纳米颗粒的人工材料。它们的传导机制是基于热辅助隧穿，并敏感地依赖于介电环境。具有可旋转偶极连接分子的柱状SURMOF系统将生长在NGM上，具有确定的晶体取向以介导稳定的铁电秩序。在另一种方法中，SURMOFs本身作为金属纳米点二维有序阵列的非导电矩阵。这种设计将有助于在与极性（和非极性）客体分子相互作用时，在频率相关的SURMOF介电常数中发生相当大的变化。为了实现这一雄心勃勃的目标，三个专注于SURMOFs的合成和表征，ngm的制造和电学表征以及MOFs的理论原子模拟的团队的能力已经结合起来。

Tunability, porosity and conformational flexibility are key properties of metal-organic frameworks (MOFs). An emerging application field of this material class is their use in highly miniaturized sensor structures. The main goal of this project is the development of a novel sensor concept up to a proof-of-concept stage. The adsorption of analyte guest molecules in surface-mounted MOFs (SURMOFs), causing changes in their dielectric properties, is detected via associated modulations of the conductivity of a nanogranular metal (NGM) sensing layer. This sensing layer is part of a SURMOF/NGM heterostructure. NGMs are artificial materials comprising metallic nano-particles which are embedded in a non-conducting matrix. Their conduction mechanism is based on thermally assisted tunneling and depends sensitively on the dielectric environment. Pillared SURMOF systems with rotatable dipolar linker molecules will be grown onto the NGM, with defined crystallographic orientation to mediate a stabilized ferroelectric order. In another approach, the SURMOFs serve themselves as a non-conducting matrix for two-dimensional ordered arrays of metallic nano-dots. This design will facilitate the occurrence of sizable variations in the frequency-dependent dielectric permittivity of the SURMOF upon interaction with polar (and non-polar) guest molecules. In order to achieve this ambitious goal, the competence of three groups focusing on the synthesis and characterization of SURMOFs, the fabrication and electrical characterization of NGMs and the theoretical atomistic simulation of MOFs have been combined.