A ReaxFF Molecular Dynamics Simulation of the Formation of Nascent Soot Particles

Effects from temperature on the formation mechanisms of nascent soot particle from PAH monomers are studied using ReaxFF molecular dynamics simulations. At low temperatures (400 K), growth of soot particles from PAH monomers is through physical nucleation mechanism. At moderate temperatures (1600 K), PAH can only grow into dimer or trimer, which can hardly experience the phase transformation from gas phase monomers to solid phase soot particles. When the temperature increases to 2500 K, formation of soot particles is through chemical nucleation mechanism. Broken of C-H and C-C bonds leads to the formation of C-chains. Then these C-chains connect to form fullerene-like structures.