The Impact of Nitrogen Plasma Treatment upon the Physical-Chemical and Dyeing Properties of Wool Fabric

Pretreatment of wool fabric with low-temperature plasma (LTP) as an eco-friendly process was tested. The impact of plasma-treatment parameters on the surface morphology, physical-chemical, and dyeing properties of wool using anionic dyes were investigated. The LTP-treatment resulted in a dramatic improvement in fabric hydrophilicity and wettability, the removal of fiber surface material, and creation of new active sites along with improved initial dyeing rate. The nature of the plasma gas governed the final exhaustion percentage of the used acid dyes according to the following descending order: nitrogen plasma > nitrogen/oxygen (50/50) plasma > oxygen plasma > argon plasma ≥ control. Prolonging the exposure time up to 20 minutes resulted in a gradual improvement in the extent of exhaustion. Increasing the ageing period up to 100 hours resulted in a slight decrease in the extent of acid dye uptake. Increasing the salt concentration up to 5 g/L and the dyeing temperature up to 95°C resulted in an enhancement in the extent of exhaustion. The extent of improvement in dye bath exhaustion, using low temperature nitrogen plasma (LTNP)-treatment, was determined by the nature of the anionic dyes.