Novel eco-friendly bio-nano-hybridized woolen felts for effective oil/water separation

Herein, a novel eco-friendly oil/water separation membrane was fabricated by bio-nano-hybridized surface modifications of waste woolen felt, which are inexpensive and biodegradable raw material. The bio-nano-hybridized surface modification was performed by decoration of the felt with polydopamine (PDA) in the presence of TiO2 and then Ag nanoparticles loaded onto the PDA layer by in-situ reduction, followed by treating the woolen felt@PDA-TiO2-Ag with a thiol having long alkyl chain (DDT) to fabricate the woolen felt@PDA-TiO2-Ag-DDT. FT-IR, FE-SEM, TEM, AFM and XRD analyses were performed to examine the surface structure and morphology of the modified woolen felts. Results revealed that low surface energy as well as nanostructured roughness were created through the modification process. The modified felt showed superhydrophobicity with water contact angle of 155o and excellent water/oil separation performance. It was also demonstrated that the densities of the membrane can be adjusted by the bio-nano-hybridized modification and the water/oil separation capability can be enhanced.