Development of aligned carbon nanotubes by an in situ chemical vapor deposition process: incidence of the operating conditions

D. ZILLI; S. N. GOYANES; G. R. RUBIOLO; A. L. CUKIERMAN

Tucumán, Argentina

Workshop; Quilmes Nanoscience Workshop; 2003

Carbon nanotubes (CNTs) have gained increasing interest in recent years owing to theirpotential applications. Several processes have been explored for CNTs synthesis. Amongthem, the chemical vapor deposition (CVD) process based on pyrolysis of certain organicmetalcomplexes, which contain both the metal species and the carbon source required forCNTs nucleation and growth, has a number of advantages. It leads to CNTs perpendicularlyaligned to the substrate over relative large-scale surfaces (up to several square centimetres)that can be readily transferred onto other various substrates. Though this process has beenearlier applied, the incidence of the operating conditions on the characteristics and/orproperties of the developed CNTs have not been systematically examined. Within thiscontext, in the present work, CNTs are synthesized by pyrolysis of iron (II) phtalocyanineunder  Ar/H2 in a flow reactor heated by a dual furnace with independent temperaturecontrollers. Main conditions studied include gas composition (Ar/H2: 1:1, 1:2 v/v), total gasflow rate (10-100 cm3/min), pyrolysis temperature (750-1050 °C), and the precursor s mass(0.05, 0.3 g). The CNTs obtained under the different operating conditions are examined byscanning and transmission electron microscopy (SEM and TEM). CNTs features, i.e. lengthand vertical alignment, are found markedly dependent on the conditions used. Deposition ofCNTs onto ceramic and metallic substrates is also investigated.