Natural silk fibers incorporated aramid nanofibers sponges for efficient oil/water separation

Industries and daily life produce large amounts of oily wastewater. For the efficient and economical separation of oil and water mixtures, silk microfibers (SM) were integrated with aramid nanofibers (ANF) to fabricate a hydrophobic and oleophilic O-SM/ANF sponge through a facile HCl volatilization method followed by hydrophobic surface modification. The O-SM/ANF sponges showed low density of 0.04–0.13 g/cm 3 , water contact angle of 130–138°, high absorption capacities up to 11.4–20.7 times of their own weight, and can be recycled for > 20 times by manual squeezing. The O-SM/ANF sponges exhibited high separation efficiencies for both immiscible oil/water mixtures and oil/water emulsions, desirable as oil/water separation materials.