Dyeing properties of wool fabrics treated with atmospheric pressure plasmas

The dyeing properties of wool treated with atmospheric pressure plasma are investigated in terms of exhaustion with dyeing time, absorption isotherm and C-t/C-infinity. versus t(1/2) curves, dyeing rate (half-dyeing time), exhaustion at dyeing equilibrium, and color fastnesses. The wettablity and surface morphology of the plasma-treated wool are also analyzed. Through both air/helium and oxygen/helium atmospheric pressure plasma treatments, the water contact angle of the fabric decreases from 132.4 degrees to 0 degrees and water penetration time drops from more than 2000 s to 1 s or 2 s. The scanning electron microscopy analysis shows etching and crack marks on treated fiber surfaces. The plasma treatments greatly increase initial dyeing rate, shorten half-dyeing time, t(1/2), and the time to reach dyeing equilibrium, although the final exhaustion and color fastnesses do not change. The Langmuir adsorption equation is also valid for the plasma-treated wools dyed with an acid dye. (c) 2008 Wiley Periodicals, Inc.