Metal-organic framework polymer composite enhancement via acyl chloride modification

Ideal mixed-matrix composites fabricated from metal-organic frameworks (MOFs) and polymers should exhibit good compatibility between components, high adsorptivity, and fast and efficient reactivity. Often, poor compatibility between MOFs and polymers results in interfacial defects, which lead to underperforming materials. In this work the MOF UiO-66-NH2 was modified using various acyl chlorides to tailor MOF compatibility and dispersion within mixed-matrix composites and electrospun fibers to enable better protective suits and filters. MOF crystal structures were unaffected and high surface areas were present after acyl chloride treatment. Most treated MOFs had increased reactivity towards soman (GD) and the simulant dimethyl p-nitrophenylphosphate relative to the baseline MOF, and this enhanced reactivity was probably because of better wetting behavior towards the agents. Chlorine and 2-chloroethyl ethyl sulfide uptake of modified MOFs was similar to uptake in the baseline MOF, while nitrogen dioxide and GD sorption capacity decreased for all modified MOFs due to exhaustion of amine sites and pore blockage, respectively. Overall, modification of the MOF with acyl chlorides resulted in better polymer compatibility, retained adsorption capacity for multiple chemicals and even increased reactivity towards GD. The structure-activity processing insights gained from this work will lead to the design of more effective protection equipment such as filters, clothing/suits and membranes. Published 2020. This article is a U.S. Government work and is in the public domain in the USA

Automated summary

The modification of MOF with acyl chlorides improved polymer compatibility, retained adsorption capacity for multiple chemicals, and even increased reactivity towards GD. The insights gained from this study will lead to the design of more effective protection equipment such as filters, clothing/suits, and membranes.