Design and Preparation of Porous Meta-Aramid Fibers Filled with Highly Exposed Activated Carbon for Chemical Hazard Protection Fabrics

Abstract

Chemical hazard protection safety and wear comfort of chemical protective clothing (CPC) are vital for the chemical personnel involved. Unfortunately, low air permeability and poor durability of adsorbate loading from conventional protective textiles coated with porous substances still cause tremendous threats to health and reduce working efficiency. Herein, to solve these limitations, highly exposed activated carbon (AC) nanoparticles are locked inside the chamber of porous meta-aramid fibers (PMIAs) from physical blending and wet-spinning as well. By controlling the pore parameters of PMIA fibers via adjusting the coagulation conditions (bath temperatures and bath composition) during the nonsolvent phase separation (NIPS) process, not only the inner AC is exposed highly but also the adsorption capability of AC-filled meta-aramid fibers to hazardous gases and corresponding mechanical properties is optimized. The resultant fiber (with 20 wt % AC) demonstrates a high adsorption capacity for benzene (102.26 mg/g), sufficient tensile strength (1.82 cN/dtex), and is recyclable. Finally, the further developed fabric from this composite fiber also offers a higher air permeability (11.4 cm 3 s −1 cm −2 ) and a firmer loading of AC compared to commercial CPC (FFF02). This work should serve as a source of inspiration for improving the comfort and safety of CPC.

Preparation of Meta-Aramid Filaments with High Strength and UV-Resistant Properties through Wet Spinning

“…It may be due to the lower concentration of the coagulation bath, where the nPMIA filaments had a faster diffusion rate during coagulation, which promoted the formation of a brittle cortex structure. Moreover, the discrepancy in desolvation rate between the inner and outer layers, coupled with the generation of nonuniform shrinkage-induced internal stress, resulted in an increased formation of voids that adversely impacted the mechanical strength of the filaments . In order to verify the above hypothesis, the cross-sectional topography of P1-nPMIA filaments was analyzed (Figure g).…”

“…When the gel bundle was stretched, the surface solidified intensely and easily formed a brittle and hard cortex layer, thereby hindering diffusion. Meanwhile, the double diffusion of solvent and coagulant will generate pores or grooves within the filaments . Excessive surface coagulation will result in the formation of numerous voids inside the nPMIA filaments, thereby impacting its strength.…”

“…Poly­(m-phenylene isophthalamide) (PMIA) filaments have been widely applied in thermal protective clothing, filter materials, flame-retardant decorative clothing, and electrical insulating paper, becoming an irreplaceable material due to their stable chemical properties, excellent heat resistance flame retardancy, and chemical resistance. − Wet spinning is the most favored method for preparing PMIA filaments, and the coagulation-forming process is key in wet spinning, directly affecting the structure and properties of filaments . However, it is found through collection that there are few mechanistic studies on the coagulation process of wet spinning and very few reports on this aspect.…”