Contact Angle Decay Model to Study Plasma Afterglow Activation of Polymers

Abstract

Treatment time-dependent contact angles of polyethylene samples activated in the afterglow of a dielectric barrier discharge are investigated. A semi-empirical model is proposed describing the contact angle behavior by two simultaneously occurring exponential decay processes. Fitted parameters are used to examine the influence of barrier thickness, gas flow rate and electrode length on the contact angle decay. Results reveal a faster contact angle decrease with reduced barrier thickness and higher gas flow rate. The influence of each activation process varies when the gas flow rate and the electrode length are changed. The different speed and behavior of contact angle decay are explained by altered active species densities and a changing extent of UV radiation.

Plasma afterglow treatment of polymer powders: Process parameters, wettability improvement, and aging effects

“…To increase efficiency of the presented process and for improved powder activation efficiency we redesigned MCD1. Different process and geometry parameters were systematically investigated in a previous study regarding their ability to induce a quick contact angle decay . We found a reduction in barrier thickness and a high gas flow rate beneficial to obtain a fast activation.…”

Water sorption and diffusion in cellulose acetate: The effect of plasticisers

“…Considering that the change in contact angle over time appears to be mostly due to absorption rather than spreading and that it depends on two absorption process, the equation used by Oberbossel et al (2016), Eq. (3), who also described two distinct absorption processes, was fitted to the experimental data.…”

Effect of airflow on the discharge uniformity at different cycles in the repetitive unipolar nanosecond‐pulsed dielectric barrier discharge

“…As a reliable method to directly generate nonequilibrium plasma at atmospheric air, dielectric barrier discharges (DBDs) have the advantage of flexible structure, good cost performance, low gas temperature, as well as sufficient concentration of active species. [ 1,2 ] Therefore, they have wide application prospects in many fields, such as thin‐film deposition, [ 3–5 ] ozone generation, [ 6,7 ] biomedical treatment, [ 8–11 ] material processing, [ 12–14 ] flow control, [ 15,16 ] and so on. A DBD has three typical discharge modes, namely filamentary mode, patterned mode, and diffuse mode.…”