Crystalline materials with high nanoscale porosity have the potential applications in a wide range of fields such as catalysis, gas storage, filtration, and energy conversion and storage. Covalent organic frameworks (COFs) are a customizable and predictable class of materials with attractive crystallinity and porosity. When synthesized in films with nano- or micron-scale thicknesses, COFs become viable candidates for applications in engineered systems, e.g., flow-through filtration. However, moving to these applications requires the development of an understanding of the mechanical properties of these COF membranes, which are key to their successful use in applications, particularly where the films may be required to self-support.<br/><br/>Here, we present our work on rigid, freestanding COF-1 membranes with micron-scale thicknesses that have been synthesized using two different routes: a room temperature solvent vapour annealing approach and thermal annealing. We have compared the membranes produced from these two procedures using a range of techniques, including microscopy (optical, scanning electron and atomic force), FTIR, x-ray diffraction, and gas adsorption. We have also measured the Young’s modulus of the films using nanoindentation, providing new insight into COF mechanical properties. These measurements allow us to begin considering how free-standing COF membranes might be incorporated into applications.

Structural and mechanical properties of self-supporting covalent organic framework membranes obtained via two different preparation routes

2019 Spring National Meeting

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