Characterization and performance of coupled atmospheric pressure argon plasma jet with n-hexane electrospray for hydrophobic layer coatings on cotton textile

In this study, we developed an apparatus by combining n-hexane electrospray and atmospheric pressure argon plasma jet for deposition diamond like carbon (DLC) layer as a hydrophobic film on cotton textile. n-Hexane was used as a hydrocarbon precursor for preparing ionized spray for atmospheric pressure plasma (APP) jet. In order to characterize the plasma, electrical measurement and optical emission spectroscopy (OES) were employed. The electron excitation temperature of the APP was estimated by Boltzmann plot method. Water contact angle (WCA) measurement was used to evaluate the hydrophobicity of the samples. The results showed that the water contact angle of these samples increases after treating by a combination of n-hexane electrospray and the APP jet. Considerations of aging effect on the samples clarified that the samples coated with longer times show better withstand against aging effect. Washing durability investigation of the samples showed that the hydrophobic property of the samples has acceptable durability in 50 washing cycles. Formation of diamond like carbon (DLC) coating on the substrates was proved by Raman and X-ray photoelectron spectroscopy (XPS) then characterized by FE-SEM analysis, energy dispersive spectroscopy (EDX) and X-Map probe. The results of this work were compared to the original one whose liquid precursor was ethanol. It was concluded that n-hexane precursor could result in better hydrophobicity comparing with that of ethanol precursor.