Evaluation of the membrane performance of ultra-smooth silicon organic coatings depending on the process energy density

Plasma-enhanced chemical vapor deposition (PECVD) can be used to apply thin layers to plastics with a wide range of customizable functionality. The selective permeation properties of the layers are particularly interesting for the application field of membrane gas separation processes. In order to be able to produce plasma polymerized membranes in an application specific manner, it is necessary to be able to correlate the plasma process parameters, such as the energy density introduced into the system, with the coating and thus separation properties. Within the scope of this work, different layers produced in a Plasma-enhanced chemical vapor deposition process were investigated with respect to their growth behavior, topographic and chemical properties as well as permeability to evaluate their performance as separation layers of a membrane. The results of the investigations show a strong dependence of the layer and separation properties on the pulsed microwave (MW) power coupled into the process. Energy input was varied over the MW power level as well as the MW pulse duration. Analysis shows the highest permeation and separation performance of the produced layers in the low energy density range of the process.