Rapid Synthesis of Metal-Organic Frameworks Onto Polyester for the Filtration of Particulate Matter

In light of the COVID-19 pandemic and an increasing amount of air pollution, there is a current need for face coverings that are more effective at filtering particulate matter than disposable medical masks and fabric masks. Metal-organic frameworks (MOFs) are highly porous, crystalline compounds that have been used to filter particulate matter. The scalability issues that arise from prior work are that the MOF formation can take hours to days and requires harsh organic solvents, such as DMF. In this work, we synthesized a zirconium (Zr)-based MOF (UiO-66) on the surface of polyester fabric using sequential dip coating (SQD) within minutes using water as the solvent.

To begin, small swatches of MOF fabric (2-inch diameter circles) were made and tested for particulate matter filtration. Then, the process was scaled up using a roll-to-roll coating process to make full sized face masks (6” by 9” rectangles). The full-sized MOF-fabric masks showed enhanced filtration capacity and passed the ASTM F3502-21 Level 1 standard for face coverings, which is filtration greater than 20% efficacy and a pressure difference fewer than 15 mmH2O when tested at an air flowrate of 85 liters per minute. In this study, we show that we can synthesize large area MOF-fabrics in aqueous medium for better particulate matter filtration within minutes.