(259g) Identifying Crystal Morphologies to Optimize Growth Kinetics of Covalent Organic Frameworks – an Example of Cof-5

Covalent Organic Frameworks (COFs) have gained significant attention in the field of material science over last two decades [1]. 2D boronate-ester linked frameworks like COF-5 are porous, crystalline, organic polymers with low density, that have numerous applications such as gas storage and as membranes for various industrial purification applications. COF-5 exhibits high thermal stability, high surface area and permanent porosity, widening the scope of its applicability. Controlling crystal morphology is the most critical variable to maximize the applicability of these polymeric frameworks. Computing steady state and dynamic morphologies of COF-5 in a specific environment is essential for gaining comprehensive understanding of ways to control it. Face-specific growth rates have been previously utilized to understand these morphologies. The faces of these crystals are divided into three classes: flat, stepped and kinked faces, according to the Hartman-Perdok theory. This theory also states that layer by layer growth occurs on the F-face of the crystal lattice, which is the basis of studies conducted on COF-5 framework. Attachment energy calculations have been carried out along with kink sites distribution calculations to evaluate growth rates. The predicted rates have been used to understand the morphology of COF-5 crystals and the results are compared with experimental values, providing a deeper insight on optimizing process conditions for morphology control.