Covalent-organic framework as a template to assemble carbon nanotubes into a high-density membrane: computational demonstration

Carbon nanotube (CNT) membranes have a wide range of important technological applications; however, the fabrication of high-density CNT membranes is challenging. Using molecular simulation, we demonstrate that a covalent-organic framework (COF-8) can act as a template promoting (9, 9) CNTs to assemble into a homogeneous high-density membrane. Surprisingly, the templated assembly is unique for (9, 9) CNTs and not observed for smaller or larger CNTs. The microscopic analysis based on the potential of mean force reveals that the highly selective assembly of (9, 9) CNTs into COF-8 is thermodynamically favorable, in contrast to other CNTs. This proof-of-concept computational study proposes a bottom-up strategy to produce high-density CNT membranes, and has a significant implication in CNT applications.