Two-step process that allows controlling independently roughness and chemical composition of plasma polymers, i.e., two parameters determining the wettability of such materials, is presented. In the first step a film composed of Ti nano-clusters is deposited on a smooth substrate.
Nano-cluster films of different roughness can be obtained depending on deposition time. In the second step the nano-cluster films are overlaid by a thin layer of plasma polymer having the desired chemical structure.
This approach allows the tuning of wettability of the deposited films to as much as 50% of the wettability of the films having the same chemical structure but deposited on a smooth substrate.