ESR study on fibers treated with atmospheric dielectric barrier discharge plasma

In order to further understanding the mechanism of atmospheric dielectric barrier discharge, the production and influence factors of free radical trapped in fibers treated by plasma were investigated by using electron spin resonance (ESR) spectroscopy. The ESR spectra shapes and intensity of treated wool samples change with increasing the plasma time during. The absence of obvious spin signals in wool samples pre-conditioned in 100% RH before plasma treatment indicates that free radical formation is inhibited in fibers with the highest moisture regain, which could be accounted for the function of absorbed water molecules in the fiber matrix. Big differences are evident in the ESR spectrum among different type of fibers under the same plasma condition. It can be concluded that the plasma duration, fiber moisture content and macromolecular structure have great influence on the outcome of free radicals induced by the atmospheric dielectric barrier discharge.