The influence of DBD plasma treatment on the dielectric loss tangent and surface morphology of fibrous polymeric materials

Abstract

The aim of this work was to investigate the influence of dielectric barrier discharge (DBD) plasma treatment during 30 and 60 seconds on the fibrous polymeric materials made of cotton, polyethylene terephthalate and polypropylene by recording the frequency dependence of the dielectric loss tangent. Furthermore, the changes in the sample surface morphology were observed using scanning electron microscopy (SEM). By comparing the frequency dependence of the dielectric loss tangent, the same trend with increasing the frequency was noticed for both untreated and treated samples, after 0.5 h as well as 2 and 7 days after plasma treatment. The changes in the value of dielectric loss tangent are small, but it can be noticed that the plasma effect on the cotton sample was maintained after 7 days, which is less noticeable for the samples made of polyethylene terephthalate and polypropylene. The SEM analysis of the cotton sample showed micro cracks on its surface as a result of plasma etching, while the polyethylene terephthalate fibers appeared darker and rough after the plasma treatment. The changes were more obvious on the samples treated 60 seconds compared to samples treated 30 seconds. There are no significant changes in the polypropylene sample surface morphology.