A theoretical characterization of the interaction of water with oxidized carbonaceous clusters

Quantum mechanical calculations are used to study the interaction of water molecules with oxidized carbonaceous clusters, modeling soot primary particles emitted by aircraft engines. First, the interaction of atomic oxygen with the face or the edges of small graphite crystallites of nanometer size is modeled at a quantum level, leading to the formation of graphene-oxide-like clusters. Then, a similar quantum approach is used to characterize the adsorption of one to six water molecules on the resulting clusters, in order to better understand, at a molecular level, the role of such oxidized sites on the hydrophilic properties of soot. It is shown that epoxide-like sites can participate in the hydrophilic behavior of soot primary particles although they are less attractive for water than hydroxyl or carboxyl sites.