Abstract: Significant research efforts have focused on understanding the relationship between material structure and functional properties, with the ultimate goal to be able to design and produce bespoke materials optimized for specific purposes. This never-ending quest has recently led to the discovery of a rapidly expanding subclass of porous materials known as metal-organic frameworks (MOFs). The potential of MOFs appears to be immense due to the accessibility of a nearly-infinite number of both organic and inorganic components – building blocks that can be easily self-assembled in extended networks. Taking advantage of modular composition, high surface areas, adjustable pore sizes, and tunable surface properties, MOFs are emerging as one of the most promising materials for energy and environmental applications.
The main objective of this thesis is to explore different aspects concerning MOF materials, building on the knowledge from several subtypes of MOFs developed primarily in Prof. Eddaoudi’s group. In particular, this dissertation expands the diversity within and utility of the following MOF subtypes: MOFs comprised of sql supermolecular building layers (SBL), MOFs based on fluorometalates, and zeolite-like MOFs (ZMOFs).
Whenever feasible, emphasis was placed on the synthesis and application of MOFs as supported thin films, particularly as the sensitive element of capacitive gas sensors or as a selective layer of composite membranes for gas separation.
Some of the highlights from the results obtained in the course of this study include:
- Introduction of MOFs to the field of reverse selective (CO2/H2) membranes for hydrogen purification. Notably, despite the challenges associated with the preparation of continuous “defect-free” MOF membranes, three different types of adsorption-driven MOF membranes have been synthesized and have shown a preferential permeation of CO2 over H2. In addition, the diffusion driven butane isomers separation was realized in ana-ZMOF membrane, being close to or even overperforming benchmark materials reported in the literature for the separation of both gas pairs.
- Identification of an appropriate MOF compatible with the developed capacitive-based sensor system and capable of the detection of sulfur dioxide in ppb level.
- Discovery of a ZMOF material with a new unprecedented zeolitic topology and its ability to separate propylene from propane upon the difference in diffusion of the adsorbates.