IR spectroscopic investigation of the structure of water–fuel microemulsion for diesel engines

The structures of a microemulsion formed by a surfactant (ammonium oleate), water drops of a linear size of 1–3 $\mu$m, and a diesel fuel has been investigated using IR spectroscopy. It has been found that ammonium oleate molecules in the microemulsion are dissociated on the positive NH$_4^+$ ion and the negative ion of the remaining part of the molecule, which forms the hydrogen bond with water molecules. This increases the rate of water, evaporation and leads to the more complete combustion of the diesel fuel. As a result, the concentration of harmful nitrogen oxides and soot particles in the exhaust gas of the diesel engine decreases.