Three-dimensional growth mechanism of cosmo-mimetic carbon microcoils obtained by chemical vapor deposition

Abstract

Cosmo-mimetic carbon microcoils with a three-dimensional helical/spiral structure similar to deoxynucleic acid, having coil diameters of 3–6 μm and coil lengths of 5–8 mm could be obtained by the catalytic pyrolysis of acetylene. A three-dimensional growth model of the carbon coils, based on the anisotropy for the carbon deposition among three crystal faces, is proposed. The microcoiling morphology is formed by the rotation of a Ni catalyst grain, from which six fibers grow and coalesce with each other, followed by the formation of two fibers, and these two fibers entwine in the same direction and at the same speed of about one cycle per second around the coil axis.