Polymer of intrinsic microporosity (PIM) based fibrous mat: combining particle filtration and rapid catalytic hydrolysis of chemical warfare agent simulants into a highly sorptive, breathable, and mechanically robust fiber matrix

Abstract

Highly selective and lightweight protective suits featuring excellent breathability, mechanical robustness, and catalytic degradation performance toward chemical warfare agents (CWAs) are highly desirable for first responders and the military. However, current multilayered state-of-the-art chemical/biological (CB) protective textiles containing activated carbon and separate aerosol-protective layers exhibit several drawbacks including high thermal burden and secondary contamination. Herein, we present for the first time, a highly sorptive, breathable, and mechanically strong aerosol-protective layered fabric with prominent catalytic degradation capability of CWA simulant, through novel material selection and engineering design. The electrospun polymer of intrinsic microporosity (PIM-1) fiber web with hierarchical porosity is used as a matrix material, preventing toxic gas penetration while providing pathways for air and water vapor molecules. Polyacrylonitrile (PAN) nanofibers assembled with PIM-1 fibers via a layer-by-layer electrospun-deposition approach are shown to achieve significantly enhanced mechanical integrity and filtration efficiency, due to the high polar chemical structure and small fiber diameter of PAN. The subsequent incorporation of UiO-66-NH2 particles, a Zr-based metal-organic framework (MOF), further enhances the sorption capacity while maintaining excellent filtration efficiency, mechanical strength, and breathability, and also endows the fiber web with remarkable catalytic degradation towards CWA simulants. The resulting PIM/PAN/MOF composite fiber mat demonstrates unprecedented integrated properties with water vapor transmission rate of 1,013 g/m2·24 h, surface area of 574 m2/g, increased tensile strength (more than 70 times compared to neat PIM-1 fiber web), and PM2.5 and PM10 filtration efficiency of 99.88% and 99.94%, respectively, comparable to commercial polypropylene (PP) non-woven textile. This facile and effective fabrication of such a multifunctional composite fiber mat is valuable for the design of protective garments in health care, personal protective gear, and law enforcement and military uniforms.