Date of Defense
9-12-2024 1:00 PM
Location
F3 - 136
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Chemistry
College
COS
Department
Chemistry
First Advisor
Prof. Yaser E. Greish
Keywords
Metal organic frameworks, Covalent organic frameworks, oxidation, imines, amides, cycloaddition, epoxides, monomers, polymerization, and carbamates
Abstract
Reticular materials have enlisted tremendous interest from researchers across the globe in the last two decades. This heightened interest stems from the novelty in structure and chemistry that renders them peerless in multiple fields such as medicine, energy, and environment. On the environmental research front these materials have found applications in mitigation of different pollutants such as CO2 which is the most important greenhouse gas through storage and conversion, catalysis of CO2 conversion into useful products. Furthermore, these materials have also proven to be effective sorbent materials for many toxic compounds that find their way into freshwater systems such as heavy metals, pesticides, and other organic compounds. On the other hand, owing to their conductive behavior that is influenced by their narrow band gap properties, reticular materials are excellent photocatalysts in organic synthesis reaction among which polymerization of different monomers into pure polymers stands out. For all these applications to be sustainable and attract adoption by end users, reticular materials must be engineered to limit costs, and ensure value for money in the products used. This ultimately boils down to the stability, efficiency, and ruggedness of these materials. Metal organic frameworks (MOFs) have suffered some setbacks when used in aprotic solvent environments and thus need to fix their bridges (linkers). Moreover, creating composite materials involving 2-D MOFs and 1-D nanofibers would enable the creation of stable membranes that can be used in remediation applications. In this work we have engineered Metal organic frameworks (MOF-901 into MOF-997) by converting the imine linkages into amide bonds. The two MOFs have been tested for their photocatalytic efficiency in the cycloaddition of CO2 on to different epoxides to yield cyclic carbonates that are highly sought after as industrial materials in the manufacture of different products. Our findings prove that both MOFs are effective photocatalysts with MOF-997 achieving highest yields in mild conditions. Secondly, we have synthesized two COFs (Pyrene-COF and Porphyrin COF) for adsorption and degradation of pesticide residues from water and as photocatalysts in the polymerization of Methyl Methacrylate (MMA) into Polymethyl Methacrylate (PMMA). Results show high potential for the pyrene COF in the adsorption and degradation of carbamates especially carbosulfan and porphyrin COF effectively catalyzing polymerization process while achieving high molecular weight (150000-25000 g/m) for PMMA with a narrow polydispersity index (PDI).
Included in
SYNTHESIS AND CHARACTERIZATION OF METAL-ORGANIC FRAMEWORK NANOSTRUCTURES AND EVALUATION OF THEIR PHOTOCATALYTIC ACTIVITY
F3 - 136
Reticular materials have enlisted tremendous interest from researchers across the globe in the last two decades. This heightened interest stems from the novelty in structure and chemistry that renders them peerless in multiple fields such as medicine, energy, and environment. On the environmental research front these materials have found applications in mitigation of different pollutants such as CO2 which is the most important greenhouse gas through storage and conversion, catalysis of CO2 conversion into useful products. Furthermore, these materials have also proven to be effective sorbent materials for many toxic compounds that find their way into freshwater systems such as heavy metals, pesticides, and other organic compounds. On the other hand, owing to their conductive behavior that is influenced by their narrow band gap properties, reticular materials are excellent photocatalysts in organic synthesis reaction among which polymerization of different monomers into pure polymers stands out. For all these applications to be sustainable and attract adoption by end users, reticular materials must be engineered to limit costs, and ensure value for money in the products used. This ultimately boils down to the stability, efficiency, and ruggedness of these materials. Metal organic frameworks (MOFs) have suffered some setbacks when used in aprotic solvent environments and thus need to fix their bridges (linkers). Moreover, creating composite materials involving 2-D MOFs and 1-D nanofibers would enable the creation of stable membranes that can be used in remediation applications. In this work we have engineered Metal organic frameworks (MOF-901 into MOF-997) by converting the imine linkages into amide bonds. The two MOFs have been tested for their photocatalytic efficiency in the cycloaddition of CO2 on to different epoxides to yield cyclic carbonates that are highly sought after as industrial materials in the manufacture of different products. Our findings prove that both MOFs are effective photocatalysts with MOF-997 achieving highest yields in mild conditions. Secondly, we have synthesized two COFs (Pyrene-COF and Porphyrin COF) for adsorption and degradation of pesticide residues from water and as photocatalysts in the polymerization of Methyl Methacrylate (MMA) into Polymethyl Methacrylate (PMMA). Results show high potential for the pyrene COF in the adsorption and degradation of carbamates especially carbosulfan and porphyrin COF effectively catalyzing polymerization process while achieving high molecular weight (150000-25000 g/m) for PMMA with a narrow polydispersity index (PDI).