(206b) Amine-Functionalized Metal-Organic Framework Crystallization Process Design

Metal-organic frameworks (MOFs) are porous crystalline structures consisting of metal centers connected via organic ligands.  MOF crystals are typically formed via solvothermal methods, which consist of heating a mixture of metal salt, organic ligand, and solvent(s) in a sealed vessel.  Most current MOF research is devoted to crystal structure identification and application specific experimentation.  However, we examine the scalability of amine-functionalized UiO-66, a water-stable MOF with direct application potential, via batch crystallization vessels as well as a novel continuous-flow crystallization process. The flow-through crystallizer utilizes a single draft-tube in an attempt to preferentially produce larger MOF crystals and agglomerates. A recycle stream is also implemented to minimize solvent usage and provide seed crystals to the crystallizer feed. Characterization of the products is accomplished by determining the product yield as well as quality.  In particular, crystal phase, size, and porosity are examined via pXRD, SEM, and BET modeling of N₂ adsorption at 77 K, respectively.