Continuous High-Yield Production of Vertically Aligned Carbon Nanotubes on 2D and 3D Substrates

Abstract

Vertically aligned carbon nanotubes (VACNTs) have certain advantages over bulk CNT powders and randomly oriented CNT mats for applications in flexible electronic devices, filtration membranes, biosensors and multifunctional aerospace materials. Here, a machine and a process to synthesize VACNTs in a continuous manner are presented showing uniform growth on 2D and 3D substrates, including alumina fibers, silicon wafer pieces, and stainless steel foils. Aligned multiwalled carbon nanotubes (MWNT) are synthesized at substrate feed rates of up to 6.8 cm/min, and the CNTs reach up to 60 μm in length depending on residence time in the reactor. In addition to the aligned morphology indicative of high yield growth, transmission electron microscopy and Raman spectroscopy reveal that the CNTs are of comparable quality to CNTs grown via a similar batch process. A significant reduction in time, reaction products, gases, and energy is demonstrated relative to batch processing, paving the way for industrial production of VACNTs.

Multifunctional, biocompatible and pH-responsive carbon nanotube- and graphene oxide/tectomer hybrid composites and coatings

“…The simple procedure for CNT functionalization of GO fibers described here can be considered as an alternative approach to other strategies for CNT functionalization/coating of substrates (including chemical vapour deposition techniques, [91][92][93][94] substrate transfer/printing, 95 the use of magnetic fields, 96 electrophoresis, 97,98 and other substrate chemical functionalization routes 99 ), and may not be restricted to GO-based surfaces. These CNT/tectomer coatings are promising in nanoelectronics, sensor applications, catalysis, biocompatible CNT inks, cell culture and smart textile applications.…”

Aligned Carbon Nanotube Reinforcement of Aerospace Carbon Fiber Composites: Substructural Strength Evaluation for Aerostructure Applications

“…Large area (20 cm x50 cm) silicon wafers coated with catalyst by e-beam evaporation ( 5,8 . VACNT length is controlled by varying the growth time.…”

Continuous carbon nanotube synthesis on charged carbon fibers

“…[43] For practical evaluation and application in composites, CNT-grafted fibers should be produced on the tow level on a suitably large/continuous scale, ideally during fiber production. Continuous CNT-grafting at the fiber tow level has been reported for fibers that are more resilient to the harsh synthesis conditions, such alumina [44] and glass [35,45]. Nevertheless, carbon fibers are preferred in the majority of high performance structural applications, especially those that are specific stiffness driven.…”