Piezo-Actuated MOF@SAW Devices

Oberhofer/Volkmer/Wixforth联盟将开发新型的压电响应协调框架(CF)，将其放置在声表面波(SAW)器件上，以刺激和研究电场诱导的框架动力学。新型的压电响应CFS包括空间受限于刚性CFS的非束缚分子转子(ur@RCFS)、轴向安装在刚性CFS中的转子(AMR@RCFS)，以及具有巨大压电响应的铰链CFS。不同层次的理论研究将有助于模拟骨架化合物的自发极化及其介电响应特性。对于后者，将采用密度泛函紧束缚方法以及基于力场的MD方法对CFS中的矢量或激活质量输运现象进行MD模拟。为了准确描述框架建筑单元的内部静电相互作用及其对外部静电场和随时间变化的电场的响应，将引入一种新的可极化力场。

The Oberhofer/Volkmer/Wixforth consortium is going to develop novel piezo-responsive coordination frameworks (CF) which will be placed on Surface-Acoustic Wave (SAW) devices in order to stimulate and to investigate electric field-induced framework dynamics. Novel piezo-responsive CFs will be synthesized, including unbound molecular rotors (uR), spatially confined in rigid CFs (uR@rCFs), axially mounted rotors (amR) in rigid CFs (amR@rCFs), as well as hinged CFs displaying a giant piezoelectric response.MOF@SAW devices of piezo-responsive CFs shall be constructed serving a dual purpose of framework actuation on one hand (i.e. giant piezoelectric distortion of CFs, stimulated rotation of CF-mounted dipolar rotors), as well as detection of the dielectric response function, on the other hand. Theoretical investigations at different levels shall serve to model the spontaneous polarization of framework compounds and their dielectric response characteristics. For the latter, density functional tight binding approaches as well as force-field based MD simulations of vectorial or activated mass transport phenomena in the CFs will be performed. A novel polarisable force field will be introduced in order to describe the internal electrostatic interactions of the framework’s building units as well as its response towards external static and time-dependent electrical fields accurately.