Manipulating the Morphology of a Metal-Organic Framework: UiO-66

Metal-Organic Frameworks (MOFs) are an emerging group of crystalline microporous materials that exhibit tunability towards various applications in gas storage, catalysts, and others. This project investigated the effects of reaction variables on UiO-66 via solvothermal synthesis. The results via the direct precipitation route at producing UiO-66 suggested that the crystallization rate was rather stagnant during the 30-day synthesis time, rendering the room temperature synthesis infeasible. Subsequently, the project investigated the effects of stirring time of the reactants for the first time in solvothermal synthesis, temperature, reaction time, modulator ratio, and reactant concentrations, on the morphology of UiO-66. Finally, the project studied the effects of adding glycols as co-solvents on UiO-66 crystal morphology. It was observed that only using ethylene glycol as a co-solvent successfully reformed the morphology of UiO-66 crystals from rounded octahedral crystals to anisotropic needle-like fibers. The results also indicated that diethylene glycol significantly improved the crystallinity of UiO-66 than triethylene glycol did.