A novel cost-effective kapok fibers and regenerated cellulose-based carbon aerogel for continuous oil/water separation

The development of cost-effective, environmentally friendly, and reusable superabsorbent materials for removing oil spills from water presents significant challenges. Herein, a novel, cost-effective, environmentally friendly, and reusable carbon aerogel (KRxCA) was synthesized by combining kapok fibers (KF) with hardwood pulp regenerated cellulose, dissolving in a mixture of N-methyl morpholine-N-oxide monohydrate (NMMO) and deep eutectic solvent (DES), which is named co-solvent DNS. This carbon aerogel presents remarkable compressibility, elasticity, and fatigue resistance, maintaining maximum stress after 100 cycles at 50 % strain due to its three-dimensional network of carbonized hollow tubular KF fixed by carbonized regenerated cellulose. The water contact angle (144.7°) indicates the excellent hydrophobicity of the KR10CA, demonstrating the potential for efficient oil/water separation. The resulting ultra-light (3.78 mg cm−3) and high porous (98.9 %) KR10CA exhibits exceptional oil sorption capacity (137.5–371.7 g⋅g−1) and retains 89.3 % of its sorption capacity after ten extrusion cycles. Additionally, as a filter membrane, the KR10CA effectively separates n-hexane from water with a high flux rate (21972.7 L m-2h−1). Therefore, the carbon aerogel derived from renewable resources presents itself as a cost-effective and environmentally friendly oil/water separator for practical application.