A universal mechanism could explain the formation of carbon nanoparticles in interstellar and terrestrial environments.
Carbon nanostructures that formed in circumstellar envelopes around carbon-rich stars may have a shared chemical origin with soot particles produced by fuel combustion. The same reaction mechanism may underpin each process, KAUST researchers have shown. The proposed mechanism could also lead to improved methods for carbon nanomaterial manufacture.
Carbon-rich nanoparticle formation — whether interstellar or combustive in nature — is thought to rely on compounds called polycyclic aromatic hydrocarbons (PAHs), which are akin to clusters of fused benzene rings held together by shared carbon-carbon pi-bonds. Several mechanisms have been proposed to explain how PAHs could combine with other carbon molecules to grow into soot and related carbon nanoparticles.
“All these studies, however, are insufficient to explain the inception of ‘peri-condensed aromatic hydrocarbons’ with only pi-bonds between carbon atoms, which can be present in large amounts in flames,” says Hanfeng Jin, a postdoc in Aamir Farooq’s labs, who led the research. “We have proposed a new mechanism that explains the nucleation of peri-condensed aromatic hydrocarbons.”
