Polymer-supported metal-organic frameworks for adsorption and catalysis

Abstract

Two methods for the incorporation of MOFs into polymeric support structures were proposed. The first was to use emulsion templated polymeric foams to create three dimensional structures with high permeability. Data were collected for two different polymers and a variety of material compositions and MOF loadings. The results indicated that a portion of the MOF particles became inaccessible to some adsorbates when embedded in hydrophilic material due to stronger interactions between the polymer and MOF resulting in complete encasement of the MOF particles. MOF accessibility could not be recovered via modification of the synthesis or emulsion structure. Hydrophobic polymeric materials allowed for much higher MOF accessibility both due to increased void volume in the polymer structure and poor interactions between the polymer and the MOF. The second method was to embed MOF particles in polymer fibers produced via solution blow spinning. This method allowed direct application of fibers to a surface without specialized equipment or polymers. The data indicated that fiber size and texture could be controlled via manipulation of process variables, although the MOF became inaccessible due to being embedded under a glassy polymer layer on the outside of the fibers. MOF accessibility was recovered via the incorporation of a non-solvent to create a ternary system and allow for phase separation and breath figure formation, disrupting the glassy layer. Both methods were found to be effective for providing mechanical stability and structure while preserving MOF accessibility.