dc.contributor.author |
Rahbani, Noura Georges |
dc.date.accessioned |
2021-09-23T09:00:27Z |
dc.date.available |
2022-10 |
dc.date.available |
2021-09-23T09:00:27Z |
dc.date.issued |
2019 |
dc.date.submitted |
2019 |
dc.identifier.other |
b25802483 |
dc.identifier.uri |
http://hdl.handle.net/10938/23179 |
dc.description |
Thesis. M.S. American University of Beirut. Department of Chemistry, 2019. T:7110. |
dc.description |
Advisor : Dr. Mazen Al Ghoul, Professor, Chemistry ; Members of Committee : Dr. Houssam El-Rassy, Associate Professor, Chemistry ; Dr. Digambara Patra, Associate Professor, Chemistry |
dc.description |
Includes bibliographical references (leaves 95-114) |
dc.description.abstract |
Recently in our lab, some metal-organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs) were successfully synthesized at room temperature through the reaction-diffusion framework (RDF) in a hydrogel medium. We pro- pose a development of this technique through the application of an electric field during ZIF crystal formation to further control size, morphology, and dopant in- corporation. We use a 2-D circular reactor and circular tungsten electrodes to apply potential differences in the range of ±2.0 V to a ZIF-8 system in agar gel throughout the course of precipitation. All solids are collected and characterized using scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). Doped samples are also characterized using energy-dispersive X-ray (EDX) analysis. Our study shows that the effect of the external electric field on the size and morphology of the ZIF-8 particles depends on the nature of the metal salts used. Applying a positive field reduces the size of the particles in the sulfate salt system, and leaves the nitrate system unaffected while applying a negative field increases the size and enhances the morphology of the particles in the nitrate system, while leaving the sulfate system unaffected. In both systems, the application of a negative filed induces the formation of an unidentified spherical co-precipitate in areas close to the diffusion front. Similar trends are observed in a Zn-Co mixed-metal ZIF-8 system. The application of an external field also affects the extent of cobalt incorporation into the ZIF-8 framework in both sulfate and nitrate salt systems; the application of a negative field encourages the cobalt incorporation, and the positive field drives cobalt out of the framework. |
dc.format.extent |
1 online resource (xvi, 114 leaves) : illustrations (some color) |
dc.language.iso |
en |
dc.subject.classification |
T:007110 |
dc.subject.lcsh |
Mesoporous materials |
dc.subject.lcsh |
Crystal growth |
dc.subject.lcsh |
Diffusion |
dc.subject.lcsh |
Electric fields |
dc.title |
Tuning the size, morphology, and composition of ZIF-8 and Co-doped ZIF-8 crystals through the application of an electric field in a reaction-diffusion framework |
dc.type |
Thesis |
dc.contributor.department |
Department of Chemistry |
dc.contributor.faculty |
Faculty of Arts and Sciences |
dc.contributor.institution |
American University of Beirut |