Covalent hybridizations of carbon nanotubes through peptide linkages: A density functional approach

We performed density functional theory (DFT) calculations to investigate properties of hybrid of carbon nanotubes (CNTs) through peptide linkages. Different positions of the peptide group were examined for connecting two CNTs together from their tubular tips and sidewalls. The models were firstly optimized to minimum-energy levels and the parameters were then evaluated to determine the structural properties. Dipole moments, energy gaps, binding energies, linking bond lengths and angles, and quadrupole coupling constants were the obtained parameters for defining the properties of our investigated hybrid structures. Moreover, desired parameters were also computed for the individual components and also the singular peptide-functionalized CNTs. The most significant changes of parameters were observed for that hybrid CNTs, in which the tips of CNTs were connected together through the peptide group. The results indicated that the properties of hybrid structures of CNTs are mainly dependent on the hybridization processes.