On the Issue of the Stability of Water-Repellent Infusion Liquids on Hydrophilic and Hydrophobic Silica Substrates

The macroscopic theory of the van der Waals forces has been used to calculate disjoining pressure isotherms for silicone oil and perfluorodecalin films on silica substrates. Both hydrophilic substrates and substrates hydrophobized with Teflon or polystyrene layers of different thicknesses have been considered. The performed analysis has made it possible to estimate the ranges of thicknesses of stable oil films applicable as water-repellent slippery coatings.