Understanding nanoparticle formation and oxidation processes of soot from modern gasoline direct injection engines using advanced characterisation too

With the current focus on reducing the emissions of greenhouse gases, automotive companies are increasingly looking at gasoline direct injection (GDI) engines. The direct injection system delivers desired reductions of CO2 emissions, however, it suffers from increased soot. As the GDI engine will be the most used internal combustion engine type for the next couple decades, reduction of particulate matter emissions is a key area of interest. Knowledge of soot properties is crucial for design of suitable oil formulation and exhaust gas aftertreatment systems. To obtain a comprehensive understanding of the material characteristics a variety of analysis techniques has to be employed. While some techniques such as transmission electron microscopy (TEM) have been widely used to analyse soot, their use has yet to be improved to allow for shorter time scales. Furhter, other methods like atomic force microscopy (AFM) have either not or only scarcely been used to date. However, AFM in particular can provide information on the mechanical properties of the sample. Only by combining different techniques in a complementing way, a complete characterisation of the soot can be achieved.