RESPONSE OF UiO METAL-ORGANIC FRAMEWORKS TO THERMAL PERTURBATIONS AND MOLECULAR INTERACTIONS

Abstract

Chemical weapon attacks are a persistent and evolving global threat requiring novel mitigation and defense strategies. Porous Metal-Organic Frameworks (MOFs) are amenable for a wide-range of protective applications against hazardous chemical agents, including chemical warfare agents (CWAs), given their highly tunable chemical and structural architecture. The zirconium-based UiO MOFs, in particular, offer a high degree of chemical, structural and thermal stability making them ideal candidates for filtration and decontamination applications. In this dissertation, a combination of in situ Temperature-Programmed Infrared (TP-IR) spectroscopy and Temperature-Programmed Desorption Mass Spectrometry (TPD-MS) are applied to understand the uptake, transport and desorption interactions of the nerve agent simulant, dimethyl methylphosphonate (DMMP) and complementary benign, potential alternative simulants, including acetone, isopropanol and n-heptane. The use of CWA simulants provides detailed information on the structure-activity relationship of live CWA agents and MOFs, while minimizing the consequences of accidental exposure. To understand temperature-dependent MOF-analyte interactions, the intrinsic thermal response of UiO MOFs is investigated revealing negative thermal expansion using a combination of TP-IR, TPD-MS and synchrotron X-ray Diffraction for UiO-67 MOFs. Ultimately, this multi-technique approach enables a fundamental understanding of CWA simulant interactions with single component MOFs and informs the rational design of superior sorbent materials with diverse functionality capable of selectively capturing, transporting and degrading hazardous chemicals.