Interfacial properties of self-assembling lubricants for CO2 Emission Reduction

Minimising friction between moving engine components offers reduced fuel consumption and emissions from combustion engines. Friction can be significantly reduced by inclusion of friction-modifier (FM) additives in the lubricant oil. Organic FMs are understood to adsorb at metal surfaces, forming friction-reducing surface films. However, the dictation of surface film structure by self-assembly in the bulk and at the interface is not precisely understood. Using a combination of solid/liquid cells and a tribometer rig specifically designed for neutron reflectivity experiments, we will detail the interfacial structure of two oil-soluble surfactants as they undergo cylinder/worm-like to spherical micelle structural transitions. The surfactants are cationic didodecyldimethylammonium bromide (DDAB) and anionic dioctyl sulfosuccinate (AOT) nickel salt.