Pristine and functionalized capped carbon nanotubes under electric fields

The structural and electronic properties of end‐capped carbon nanotubes (CCN) functionalized by carboxyl, amine, amide, and hydroxyl chemical groups under the action of electric fields are investigated through first‐principles simulations based on density functional theory. Changes in the original properties of the functionalized capped nanotubes are observed due to the application of external electrical fields and the responses for different intensities are shown to be nonlinear. It is demonstrated that there are optimum values for the electric field to obtain the most stable binding energies for the studied systems. In all cases, the energy levels are rearranged to stabilize the systems and electric dipole moments are induced toward the incident electric field. It is also shown that these electric dipole moments generate polarized nanotubes and the previously weak physical interactions between molecules with the tube surface would become stronger and, by binding chemically, allow the manipulation of the intrinsic properties of the nanotubes. The structural and electronic properties of end‐CCN pristine and functionalized by carboxyl, amine, amide, and hydroxyl chemical groups under the action of electric fields are investigated through first‐principles simulations based on the density functional theory.