Facile fabrication of robust superhydrophobic cotton fabrics modified by polysiloxane nanowires for oil/water separation

The removal of oil and organic pollutants from water is highly desired due to increasing industrial oil-contaminated wastewater, as well as frequent oil spill accidents. In this paper, superhydrophobic and superoleophilic fabrics were facilely fabricated for oil/water separation application via in situ growth of polysiloxane nanowires on cotton fabrics. The polysiloxane nanowires were immobilized on the cotton fabrics through a self-assembly process of alkylsilane on the microfibers of fabrics. The combination of the hierarchical structure and the low-surface-energy polysiloxane nanowires greatly contributed to the superhydrophobicity of the fabrics. Furthermore, the superhydrophobicity remained even after they were exposed to different chemicals for 72 h and strong ultraviolet irradiation and repeated abrasion, indicating excellent stability. More importantly, the as-prepared cotton fabrics were successfully used for separating various oil/water mixtures by a solely gravity-driven process with high separation efficiency and desirable durability. The cotton fabrics are commercially available, low-cost, and environmentally friendly materials, and thus such superhydrophobic and superoleophilic cotton fabrics could be very attractive for oil/water separation and oil spill cleanup when high flexibility, strength, and chemical resistance are taken into account.