Factors and Limitations of Green, Rapid Metal–Organic Framework-Fabric Synthesis and Effects on Dual Chemical Warfare Agent Protection

Metal–organic framework (MOF) fabric composites integrate important MOF chemistry with flexible, strong fabric substrates and are useful in many applications ranging from sensing, biomedical, and filtration to catalysis. Sorption-vapor synthesis (SVS) is a recently introduced method for MOF-fabric synthesis that allows high yields and rapid reactions and is scalable. However, little is known about the effects and limitations of process parameters on the final MOF-fabric properties and performance. This work investigates process parameter–MOF property–MOF performance relationships for UiO-66-NH2 fabric composites made using a rapid, benign SVS approach and is tested for toxic chemical vapor protection applications. Repeating SVS synthesis, ∼70 min per cycle, on the same fabric substrate led to an increase in MOF loading of 0.13 gMOF/gfiber per cycle and significant change in crystal morphology. It was determined that precursor concentrations >130 mM in the starting solution resulted in nonporous, amorphous MOF formation. The benign SVS method reported here achieved >95% heterogeneous MOF yield determined through scalability experiments. The MOF-fabrics were tested for organophosphate hydrolysis and permeation of both organophosphate and vesicant toxic vapors. It was found that the number of SVS cycles used to make a MOF-fabric significantly impacted performance, and despite having increased porous MOF loading, increasing over three SVS cycles led to reduced organophosphate hydrolysis rates and protection times. This work not only presents insights into the effect of synthesis process parameters on final MOF-fabric properties but also relates those changes to performance in dual toxic vapor protection applications.