Surface activation of thin polyvinyl alcohol films by atmospheric pressure plasma jet: Influence of electron temperature

This study investigates the effects of nonthermal plasma characteristics on surface treatments of polyvinyl alcohol with various diagnostics such as Raman spectroscopy, work of adhesion, optical emission spectroscopy, and current–voltage measurements. Our findings demonstrate the importance of controlling the plasma's electron temperature and density to achieve the desired surface treatment outcomes. We show that plasma jets with varying electron temperatures are more appropriate for different surface treatments, with high electron temperatures than 1.1 eV suitable for functional group (C═O) insertion abiding macro‐scale surface roughness and low electron temperatures for plasma etching, which increased surface roughness significantly. Plasma electron temperatures between 1.1 and 1.3 eV are best for treatment as higher ones cause bond breaking while lower ones would etch the surface.