This Article reports the facile fabrication of robust and durable superhydrophobic and superoleophilic cotton for highly efficient oil–water separation based on the combination of hydrophobic octadecanoyl chain bonding and polymer grafting via surface-initiated atom transfer radical polymerization (SI-ATRP). Octadecanoyl chain-tethered and polymer-grafted superhydrophobic cotton was obtained by simultaneous treatment with stearoyl chloride and α-bromoisobutyryl bromide to generate hydrophobic cotton bearing initiating sites for ATRP (C18-Cotton-Br), followed by SI-ATRP of acrylonitrile and styrene to obtain polymer-grafted cotton (C18-Cotton-g-PSAN). The surface morphologies, chemical composition, and structural identity of the modified cotton were investigated by scanning electron microscopy (SEM), FT-IR, X-ray photoelectron spectroscopy (XPS), and the nitrogen physisorption experiments. The water contact angle (WCA), oil–water separation, oil absorption, and mechanical properties of the cotton samples were evaluated systematically. The results showed that octadecanoyl and α-bromoisobutyryl groups were successfully bonded on pristine cotton to exhibit hydrophobicity, and further polymer grafting of PSAN was realized with a high grafting density of about 0.47 nm–2. Compared with C18-Cotton-Br, after polymer grafting C18-Cotton-g-PSAN displayed enhanced superhydrophobicity with the WCA increasing from 154° to 159° due to the increased surface roughness. C18-Cotton-g-PSAN exhibited a highly efficient oil–water separation achieving 99.2%, excellent absorption capacity of 26 g/g for toluene with an easily recovered performance, and remarkable mechanical durability withstanding the severe environmental conditions. The biodegradable and recyclable C18-Cotton-g-PSAN demonstrated high selectivity for the absorbing of oil and is expected to become sustainable and highly effective materials for oil-spill cleanup and the oily wastewater treatment from households and industries. Endowed with the robust superhydrophobic durability, the superhydrophobic and superoleophilic cotton can be further woven into cotton fabric to demonstrate their versatilities.

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The individually dispersed multiwalled carbon nanotubes (MWCNTs) enable the comprehensive accomplishment of intrinsic electrical conductivity, thermal conductivity, and antielectromagnetic shielding characteristics. However, the design of an aqueous carbon nanotube (CNT) dispersant remains a significant challenge in rational balances of strong interfacial interactions between CNT/dispersant and water medium. In the current research, biomass tannic acid (TA) was selected as the building block to synthesize poly(tannin urethane) (PTU) by step polymerization of TA and toluene diisocyanate, which was examined as a novel dispersant for MWCNTs. A highly homogeneous dispersion of PTU-stabilized MWCNTs and carbon black (CB) was prepared by a simple sonification and homogenization process to form aqueous antistatic additives. Furthermore, the antistatic coating for a flexible poly(vinyl chloride) (PVC) substrate was prepared by a dip-coating method using self-made waterborne polyurethane (WPU) as a binder. The results demonstrated that the aggregates of MWCNTs were successfully debundled into individually dispersed nanotubes by taking advantage of the high π−π interaction between MWCNTs and PTU. Compared with the chemical modification, the physically stabilized MWCNTs displayed fewer defects (I D /I G ∼ 0.853). Compared with the pure WPU coating, the sheet resistivity of the MWCNTs/CB/PTU/WPU coating decreased sharply from 10 16 to 10 8 Ω at 0.5 wt % loading of MWCNTs, which met the requirement of antistatic applications. With further increase of the MWCNT content, the MWCNTs/CB/PTU/WPU coatings exhibited continually decreasing sheet resistivity and reached remarkably low surface resistance of 10 4 Ω at 2.0 wt % loading of MWCNTs, which was realized by the formation of conducting networks of synergistic MWCNTs and CB-induced low percolation threshold. The facile one-pot preparation of biobased PTU and simple production of MWCNT dispersion promise an ideal additive for antistatic and conductive-related applications, especially for flexible substrates.

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