title: Novel nanometer-level uniform amorphous carbon coating for boron powders by direct pyrolysis of coronene without solvent.
abstract: A 3 nm coronene coating and a 4 nm amorphous carbon coating with a uniform shell-core encapsulation structure for nanosized boron (B) powders are formed by a simple process in which coronene is directly mixed with boron particles without a solvent and heated at 520 °C for 1 h or at 630 °C for 3 h in a vacuum-sealed silica tube. Coronene has a melting point lower than its decomposition temperature, which enables liquid coronene to cover B particles by liquid diffusion and penetration without the need for a solvent. The diffusion and penetration of coronene can extend to the boundaries of particles and to inside the agglomerated nanoparticles to form a complete shell-core encapsulated structure. As the temperature is increased, thermal decomposition of coronene on the B particles results in the formation of a uniform amorphous carbon coating layer. This novel and simple nanometer-level uniform amorphous carbon coating method can possibly be applied to many other powders; thus, it has potential applications in many fields at low cost.
authors.affiliation: National Institute for Materials Science, Sengen 1-2-1, Tsukuba, 305-0047, Japan.
authors.forename: ShuJun
authors.initials: S
authors.lastname: Ye
authors.forename: MingHui
authors.initials: M
authors.lastname: Song
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kumakura
mesh_terms: D001895:Boron / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D055032:Electron Microscope Tomography; D006801:Humans; D057145:Nanoshells; D011083:Polycyclic Compounds / Q000737:chemistry*; D011208:Powders / Q000138:chemical synthesis*
chemical_list: D011083:Polycyclic Compounds; D011208:Powders; D002244:Carbon; C012256:coronene; D001895:Boron