The synthesis of vertically-aligned carbon nanotubes on an aluminum foil laminated on stainless steel Original Research Article

Aligned carbon nanotubes (CNTs) were grown on an aluminum foil laminated on a flexible stainless steel (SS) substrate. Lamination was carried out under a pressure of 10 MPa with simultaneously heating at 400 °C. The laminated Al foil was spray-coated with an iron chloride catalyst precursor solution and the CNTs were grown using water-assisted chemical vapor deposition at 810 °C. The CNTs grew as vertically aligned forests, approximately 600 μm in height, within 600 s without crumpling of the Al foil. The Al foil acts as a sacrificial barrier layer to grow the CNTs. The CNTs had 2–30 walls with an inner diameter of 3–8 nm. Thermogravimetric and field emission analysis of the CNTs revealed a degradation temperature and turn-on field of 643.5 °C and 0.46 V/μm, respectively. Transmission electron microscopy and X-ray photoelectron spectroscopy were used to analyze the Al–SS interface and chemical states. After removing the CNTs, the flexible SS substrate could be cleaned, recoated with Al and reused for CNT growth. Overall, this process is a repeatable and continuous roll-to-roll processable method that can be scaled up for industrial production.