The analysis of PSiFe in suspension was necessary to explain the properties of thin films at the air/water interface (Table ). The first unexpected result to be explained was the significant shift of isotherms towards a higher surface area at KCl compared to the pure water subphase. The lift-off area was shifted by up to 2×, whereas step sections were shifted by up to 5× (Table ). The separation distance between the individual PSiFe particles was more significant than the Debye length (which in this system was around 1 nm; Figure ). Thus, we neglected the electrostatic repulsion of PSiFe covered in the ionic clouds.