Stable super-hydrophobic lauryl methacrylate film fabrication on the surface of cotton fabrics in plasma-enhanced chemical vapor deposition with different duty cycles

In this paper, stable super-hydrophobic lauryl methacrylate (LMA) film on the surface of cotton fabrics was fabricated by a simple process of pulsed plasma-enhanced chemical vapor deposition (PECVD) with different duty cycles. The influence of duty cycles on the surface structure and properties of cotton fabrics was analyzed after a series of measurements. The results showed that water contact angles (WCAs) of samples were inversely proportional to the duty cycle values and exhibited the highest WCA (162°) at a duty cycle of 2%. The optimized washing durability of samples was obtained under the treatment of duty cycle of 25% and the WCA could still reach 127° after 15 laundering cycles. The formation of a micro-nano-composite structure and evenness of film could be observed by atomic force microscopy and scanning electron microscopy. Nevertheless, the sample, which was treated by plasma with a 25% duty cycle, had the best uniformity of film deposition. The results of attenuated total reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy illustrated that the LMA monomer was grafted and deposited on the surface of cotton fabrics successfully in covalent binding after PECVD treatment, and this was supposed to be the cause of the washing stability of the films. The results indicated that cotton fabrics modified with the proposed method can exhibit excellent super-hydrophobicity and washing durability, while the duty cycle was an appreciable effect factor in the modification.