Investigation into the Interface Between Salt Solutions and Hydrophobic Surfaces

When water is forced into contact with a hydrophobic surface a depletion layer, a region of low density water, is formed at the interface. In nature surfaces do not deal with pure water, rather instead they interact with various aqueous salt solutions. We study octadecanethiol, a hydrophobic self-assembled monolayer, and mercaptoundecanoic, a hydrophilic self-assembled monolayer, in various aqueous salt solutions.We use contact angle measurements, scanning electron microscopy, and surface plasmon resonance to study the interfacial properties of these surfaces.