One often mentioned advantage of plasma polymerization is the possibility to coat any type of substrate. In addition, it is often supposed that films of plasma polymers grow independently of the substrate material.
As will be discussed in this contribution, this assumption is not valid for ultrathin films (up to 20 nm). In this case properties of growing film may be influenced by substrate material and may change with increasing thickness of the film.
This will be demonstrated in this study by an example of plasma polymerized polytetrafluorethylene. Results of measuring chemical composition, water contact angle and barrier properties towards oxygen are presented in dependence on film thickness.