Density control of aligned carbon nanotubes from controlled deposition of Fe catalyst nanoparticles using the filler-added Langmuir–Blodgett technique

• Published in: Thin solid films Vol. 589; pp. 115 - 119
• Main Authors: Murata, Shigeaki, Kuriyama, Naoki, Kushida, Masahito
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.08.2015
• Subjects: Alignment; Carbon nanotubes; Catalysts; Chemical vapor deposition; Density; Iron; Langmuir-Blodgett films; Langmuir–Blodgett film; Nanoparticles; Polymer electrolyte fuel cell; Thermal aggregation; Vertically aligned carbon nanotube; Vertically aligned carbon nanotube; Thermal aggregation; Langmuir–Blodgett film; Polymer electrolyte fuel cell
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2015.05.007

A filler-added Langmuir–Blodgett (LB) technique was developed to control the number density of Fe catalyst nanoparticles to grow vertically aligned carbon nanotubes (VACNTs). Palmitic acid was chosen as the filler molecule. This technique enabled the distribution of iron nanoparticles (FeNPs) with a number density of 4.2×109 to 8.7×1010cm−2 with a mean distance between particles of 36–170nm, and the growth of VACNTs. The change in the FeNP number density was controlled after each preparation step. The FeNP number density in the Langmuir film could be controlled at a target value by adding filler to the FeNPs dispersion solution when preparing the Langmuir film. Approximately 30% of the FeNPs were transferred from Langmuir film to LB film on substrate, and in the subsequent thermal chemical vapor deposition (CVD) process, the density further decreased to approximately 20%. In summary, the FeNP number density decreased to approximately 6% of the controlled number density in the Langmuir film. The FeNPs catalyzed the growth of VACNTs during the thermal CVD process. •Catalysts were deposited on substrate by filler added Langmuir–Blodgett technique.•Vertically aligned carbon nanotubes were grown by chemical vapor deposition synthesis.•Number density of carbon nanotubes was controlled by filler mixing rate.•Honeycombed structure of catalyst accumulation was key to control.