Improved Surface Modification of Polymer Films by Energy-Compressed Dielectric Barrier Discharge With Discharge-Time-Regulated Power Source
An energy-compressed dielectric barrier discharge (DBD) in the atmospheric-pressure air is established to improve the surface modification of the polymer films. The effective discharge time of per repetitive cycle in the DBD system is adjusted by employing an active regulated power source, which can compress the energy transferred to the DBD load in the time domain. The effect of the energy compression on the surface modification of the polyethylene films is studied at different energy densities and frequencies by using the contact angle measurement, the atomic force microscope, and the X-ray photoelectron spectroscope. The results show that, at the given energy density and frequency, the surface wettability is improved by increasing the energy compression degree due to the higher surface roughness and more oxygen-containing polar functional groups. Furthermore, less energy density is needed to achieve the same level of surface wettability by increasing the energy compression degree. The reasons for the high performance of the energy-compressed DBD are the increase of the reactive species density and the enhancement of the physical and chemical interactions. As a result, the energy-compressed DBD is a superior solution for the polymer surface modification.