Loofah-Inspired Regenerated Aramid/EVOH Nanofiber Dual-Network Aerogel for Efficient Oil/Water Separation

Abstract

The high-value recycling of waste aramid fibers is crucial for sustainable resource utilization. Inspired by the loofah’s porous and robust structure, this study presented​ a novel strategy for converting waste aramid fibers into a multifunctional dual-network aerogel for efficient oil/water separation. A regenerated aramid nanofiber (ANF) solution was combined with ethylene-vinyl alcohol copolymer (EVOH) nanofibers to form an interpenetrating network skeleton. This skeleton was​ subsequently modified with polydimethylsiloxane (PDMS) to create the ANF/EVOH/PDMS composite aerogel (PANF-50). The ANF framework provided high thermal stability (a maximum decomposition temperature of 567 °C), while the EVOH nanofibers enhance interfacial compatibility, increasing the compressive strength to 63.8 kPa at 70% strain. PDMS modification confers remarkable hydrophobicity (water contact angle of 132°) and oleophilicity, resulting in a high adsorption capacity for oils and organic solvents (up to 22.3 g g–1) and excellent recyclability. Structural characterization (SEM and FTIR) revealed the successful formation of a stable three-dimensional porous network and the integration of the components. Complementary XPS analysis indicates potential interfacial interactions, such as N–H···O–Si hydrogen bonding and Si–O–C covalent linkages, which were proposed to contribute to the enhanced material cohesion.​ The aerogel achieves rapid solvent saturation within 15 s and demonstrates high efficiency, selectivity, and cycling stability in oil/water separation. This work provided a new avenue for the sustainable valorization of waste aramid fibers, breaking the functional limitations of traditional ANF aerogels and showing great potential in environmental remediation.