This Small Business Innovation Research (SBIR) Phase I project will develop a new process of low-temperature synthesis of aligned carbon nanotubes (CNTs) and nanofibers (CNFs). CNTs/CNFs are widely studied for manufacturing of novel nanomaterials and nanodevices. The prospects of this manufacturing are currently limited by the high (above 500 deg C) surface temperature during CNT/CNF synthesis, which often results in nanomaterial or device damage. We propose to develop a novel processing system where CNTs/CNFs will be grown at low temperature due to (i) delivering a supply of hydrocarbons on the surfaces of nanoparticles at low temperature using a plasma-enhanced chemical vapor deposition (PECVD) process, and (ii) selective heating of catalytic nanoparticles using catalytic exothermic reactions and radio-frequency (RF) electromagnetic fields generated by an RF source additional to that used to sustain discharge in PECVD reactor. This goal will be achieved by a combination of theoretical efforts at CFDRC and experimental research at the University of Tennessee at Knoxville (UTK). Theoretical efforts will be devoted to the analysis and multi-scale computational design of CNT/CNF synthesis using a reactor-scale simulation of gas/plasma-phase processes, a Kinetic Monte Carlo analysis of the growth of CNTs, and a Molecular Dynamic modeling of self-assembly of atoms into CNTs. Phase I will show the feasibility of the proposed concepts using existing PECVD reactors for CNT/CNF growth at UTK. Phase II will be devoted to building a prototype of manufacturing reactor for the developed processes.
Currently, CNTs are produced in very small quantities and cost more per gram than gold. The combined Phase I and Phase II efforts will result in a novel processing system for a direct synthesis of vertically aligned CNT structures at selective locations on the surfaces of temperature-sensitive materials. Immediate applications include manufacturing of CNT-based field emitters displays, pharmaceutical micro-reactors, bio and chemical sensors, probe tips for atomic force microscopes, and cold cathodes in X-ray devices.
