Hydrophobic ionic liquids at liquid and solid interfaces

The aim of the present work was to contribute for a deeper understanding of the intermolecular interactions present in ionic liquid (IL) tribofilms through the comparative study of the ILs behavior at water and at silica surfaces. Three hydrophobic ILs were investigated at the air/water interface (Langmuir trough) and at the water/silica interface (adsorption, friction and wear). The same experiments were repeated with aqueous solutions of ILs containing the anionic surfactant sodium n-hexadecylsulphate (SHS). The main conclusion was that ILs and IL + SHS solutions able to form Langmuir monolayers are those which adsorb more strongly on the silica surface and which provide better protection to surface wear.