Fabrication of a superhydrophobic cotton@LDH composite for effective oil adsorption

The development of superhydrophobic materials with inexpensive cost, and simple preparation processes is crucial for alleviating oil pollution. In this paper, cotton-based composites (cotton@LDH-SA) were prepared by an in situ hydrothermal growth and simple impregnation method. The needle-like Ni–Co LDHs growing on the surface of the cotton fibers formed micro/nano hierarchical structures, and subsequently grafted stearic acid endowing the composite with superwettability. The optimized cotton@LDH-SA possesses a superior superhydrophobicity with a water contact angle of 161.6 ± 2°. The prepared composite adsorbent exhibits excellent oil absorption performance with an adsorption capacity of more than 10 times its own mass. The adsorbent has acceptable reusability, and after 6 cycles of repeated adsorption, the adsorption rate remains at 72.4%. Given the excellent economic and renewable properties of cotton, this composite adsorbent has great potential for application in large-scale production and oil–water separation.