SUMMARY

Nanoporous molecular sieve materials like Metal Organic Frameworks (MOFs) have found a wide range of technological applications in catalysis, separations, and ion exchange due to their salient features over other contemporary sensing materials. As a result, MOFs can function as a chemical recognition layer in chemical sensors that rely on analyte adsorption. Their use in adsorption-based applications is also an area of great interest, and they have been shown to selectively adsorb specific gas molecules from mixtures. The characterization of gas adsorption in porous materials is performed predominantly by commercial gravimetric equipment, whose capital and operating costs are generally high and require relatively large amounts of sample. Thus, it is desirable to obtain reliable measure of the adsorption properties of MOF materials over a substantial range of pressure and temperature by non-gravimetric methods. The objective of this thesis research is to investigate the adsorption and diffusion characteristics of recently-identified MOF materials through the development and use of a high-pressure/high-temperature quartz crystal microbalance (QCM) device. In this regard, the proposed research is divided into four main objectives, viz. (1) Design and development of high temperature/ high pressure QCM device, (2) Measurement and analysis of adsorption characteristics of MOFs in powder form, (3) Measurement of adsorption characteristics in MOF thin films/membranes, and (4) Measurement and analysis of diffusion coefficients in MOF crystals. The results obtained in Objectives 2-4 will allow us to make important recommendations regarding the use of specific MOF materials in molecular separation applications (specifically CO2/CH4 and CO2/N2), and also lead to significant fundamental knowledge of adsorption thermodynamics in MOFs via the application of analytical adsorption models to the experimental data.