Does the hydrophilic of thin film relate to its thickness (directly) and why? Which means that the thinner film has higher hydrophilic nature than film of higher thickness, is that right?
Thank you for your fast response, so may be it depends on the substrate? Because I read a paper relates the hydrophilic and hydrophobic substrate with the density of the film (Hydrophobic substrate (or surface) has much higher density film which means more thickness than that on the hydrophilic surface (or substrare)).
So you mean; when the roughness increase, the hydrophilic nature of the substrate will increase too, right? Or may be on the contrary (The highest roughness produce the lowest hydrophilic behavior surface)?
I can't offer any experience of tension measurements but the initial growth of thin films can sometimes start with discontinuous films and hillock growth. I have a vague relocation of people referring to sticking probabilities so that a vapour molecule is more likely to attach to an existing hillock of the same material rather than the substrate. Obviously, as the deposition process continues these hillocks will grow and join to form a continuous film. I have also seen significant surface roughness with DC sputtered films when you get to micron thickness, this surface roughness is due to a entirely different mechanism.
what is the method used to prepare the film? and the interaction of any materials with substrate depend on nature of material and roughness of substrate.