Water-repellency and antibacterial activities of plasma-treated cleavable silicone surfactants on nylon fabrics

In this paper we describe how cleavable surfactants decompose into water-insoluble silanols and two water-soluble products when subjected to vacuum plasma treatment. We used Raman spectroscopic analysis to confirm these structural changes, and we performed contact angle measurements and employed scanning electron microscopy to observe the surface morphologies of these compounds. Our contact angle measurements confirm that the products had degraded on nylon fabrics during argon gas plasma treatment. All of the PEG-silicone polyesters displayed excellent water-repellency; PEG6000-silicone exhibited the largest contact angle (130°) and, hence, the greatest water-repellency. Our results indicate that the silanols that form upon plasma treatment may be useful in coatings applications. We also found that the PEG-silicone polyester surfactants impart a new function–water-repellency–to nylon fabrics; thus, we may refer to these materials as “functional” surfactants. In addition, we investigated the antibacterial properties of a nylon fabric containing two biocides; after vacuum plasma treatment, the hydrophobic surface of the nylon fabric retained its antibacterial activity and was water-repellent.