Abstract

In this work, two different plasma jet designs (typical design and with geometrical modification) operating in argon are used to examine the influence of the additional plate on the created hydrophilic polyethylene terephthalate (PET) region. The surface analyses techniques (contact angle measurements and X-ray photoelectron spectroscopy [XPS]) clearly show that the introduction of an additional plate in the plasma jet set-up only has a significant impact on the hydrophilic footprint when using a small capillary-sample distance of 2mm. Comsol Multiphysics is used to explain the effect of the plasma jet design modification on the hydrophilic footprint. The simulations reveal a completely different gas flow pattern for the set-up with the modified geometry.