DESIGN, SYNTHESIS, CHARACTERIZATION, AND EVALUATION OF SURFACE MODIFIED BORONATE ESTER COVALENT ORGANIC FRAMEWORKS

Covalent Organic Frameworks (COFs) were first reported in 2005 and are analogous to Metal Organic Frameworks (MOFs), with proposed applications in separation, storage and sequestration. Since COFs are comprised of lighter elements they are considered more advantageous for weight-sensitive applications. However, COFs are susceptible to degradation by weak nucleophiles such as water (i.e. hydrolysis). The Lavigne group has focused on developing structure-property relationships for COFs. It was previously demonstrated that the porosity of the COFs could be tailored by incorporating small alkyl chains on one monomer. Inclusion of these alkylated monomers into COF materials effectively increased the COF hydrophobicity resulting in materials with enhanced hydrolytic stability. However, the increased stability is accompanied by a decrease in pore size and subsequently, surface area. This work focused on maintaining the pore size, while increasing stability. This was achieved by attaching polymers to the surface of the framework. These modifications were made either by forming boronate esters on the surface edge of the COF, or by coordinating a polymer to the empty p-orbitals of boron on the surface face. We have found that incorporation of polymer into the framework results in increased COF stability