Analytical pyrolysis as a characterization technique for monitoring the production of carbon nanofilaments

摘要

The main step in the production of carbon nanofilaments is the catalytic nucleation and lengthening of the filament. An undesired parallel step in the production of carbon nanofilaments is their thickening by pyrolitic carbon vapor deposition consisting in an ordered polycondensation of carbon over an existing catalytic carbon nanofilament. The regular characterization of the structure of carbon nanofilaments (coated or not) is by transmission electron microscopy. However, this technique is not affordable in many cases because is expensive and complex. In the present work, the analytical pyrolysis is proposed to obtain clues of the structure of carbon nanofilaments. Several commercial carbon nanofilaments have been analyzed. The samples with a thicker soot layer evolve a higher amount of heavy PAHs in the pyrolysis runs than the ones free of soot. It has been observed that pyrene is a key compound in the pyrolytic carbon vapor deposition process and the resulting formation of soot over the carbon nanofilaments. The aim of this work is to get useful information about the quality of the carbon filaments by a cheap technique, the analytical pyrolysis.