The systems were minimised for 1000 steps and equilibrated in the NPT ensemble for 1 ns with a time step of 10 fs. During equilibration, harmonic potentials were used to restrain the aromatic core and allow the tails to relax. Their force constant was 100 kJ/mol. Despite the presence of the restraints, the large number of concentrated charged beads in the hydrophilic tails created instabilities in the inner and outer wall of the nanotubes that resulted in small holes. To ensure that the nanotube remained intact during the equilibration phase, the equilibration process was performed in three steps, and the charges of the beads were progressively increased to their normal value (-0.1, -0.5 and -1.0). The actual nanotube simulations lasted 1 µs, and the time step during the production phase was 20 fs.