Superhydrophobic cotton nonwoven fabrics through atmospheric plasma treatment for applications in self-cleaning and oil-water separation

In this study, a superhydrophobic cotton nonwoven fabric for oil-water separation was prepared by graft polymerization of siloxane under atmospheric pressure plasma in the medium of Air, N-2 or O-2. The effects of different process conditions on the contact angle, surface morphology, stability of the hydrophobic coating and the growth of nano-particles were investigated. This modified cotton nonwoven was tested for self-cleaning and oil-water separation efficiency. The surface characteristics of the prepared cotton nonwoven were systematically analyzed using scanning electron microscopy, Energy Dispersive X-ray Spectroscopy, and Fourier transform infrared spectroscopy. The water contact angle of treated nonwoven was up to 155 degrees, and the precursor and jet movement speed have great influences on the surface morphologies and stability of the coating. Separation efficiency for oil-water mixture is higher than 97% and can be repeated for at least 10 times. Moreover, the superhydrophobic nonwoven treatment showed excellent stability toward strong acid and alkaline conditions, the resulting fabrics may be used under harsh environmental conditions.