Combined atmospheric pressure plasma and UV surface functionalisation and diagnostics of nylon 6.6 fabrics

Abstract The purpose of this work is to functionalize and characterize the surface of nylon 6.6 fabrics by exposure to a novel atmospheric cold plasma coupled with ultraviolet (UV) excimer laser treatment. It was found that plasma/UV treatment does not significantly physically degrade or ablate fibre surfaces, but creates changes to surface chemistry in the form of additional functional groups (principally NH2 and COOH). These chemical surface changes are not easily analyzed with techniques such as FTIR-ATR, which was found to be too insensitive; therefore, a new low-temperature surface diagnostic dyeing method was developed, and the results of this compared with those from X-ray photoelectron spectroscopy (XPS). Mechanisms for surface changes are proposed, in which surface free radicals are created by the plasma in the presence or absence of the laser, the characteristics of which depend on the atmosphere type and plasma power used. Radical production was observed through the use of a radical scavenger in combination with UV–vis spectroscopic analysis and by electron paramagnetic resonance (EPR).