Shock-induced carbonization of phenanthrene at pressures of 7.9-32 GPa

The chemical behavior of phenanthrene during a reaction triggered by shock waves, and its influence on the physical property of phenanthrene were studied over the pressure range of 7.9-32.0 GPa. Chemical analyses showed that shocked phenanthrene included insoluble carbonaceous material containing amorphous carbon, polycyclic aromatic hydrocarbons (PAHs) with molecular weights ranging from 128 to 356, and unreacted phenanthrene. No diamond and fullerenes were detected in the shocked phenanthrene. The results indicate that reactions triggered by shock wave are dehydrogenation, which causes carbonization and radical addition reactions, and ring cross-linking. Carbonization is the most dominant and rapidly proceeded above 20.0 GPa. Thus, an abrupt increase of compressibility of phenanthrene above 20.1 GPa previously reported is caused by the drastic carbonization.