(779e) Water-Induced Interactions Between Boron-Doped Carbon Nanotubes: A Multiscale Simulation Study

Zhang, Z., University of Alabama
Turner, C. H., University of Alabama

We have deployed molecular dynamics (MD) to investigate the hydration, the water-induced interactions, and the debundling behavior of boron-doped single-walled carbon nanotubes (B-CNTs) within aqueous solutions. Partial charges on the atom sites are fit to electrostatic potentials (derived from first-principles calculations), which are used to capture the polarization effects within the B-CNTs, and this model is then used in the MD simulations.  These charges are fit with the DDEC method, which is proven to reproduce correct electrostatic potential of periodic nanotubes.

To clarify the water-induced interactions of B-CNTs, the potential of mean force (PMF) of two and three solvated B-CNTs are evaluated by MD over a range of different temperatures. The water density profiles, orientations, and hydrogen-bonds are also studied to shed light on the hydration behavior of the B-CNTs. The same properties of pristine CNTs are also investigated as a benchmark to project the effects of B-doping on the water-CNT interactions. Enhanced B-CNT-water interactions and water-induced interactions between B-CNTs are observed at more prolonged distance, as compared to pristine CNTs. These simulations provide important insight into the effects of substitutional doping of CNTs on their dispersion behavior, which is a critical issue for engineering composite materials and other CNT/graphene-based system.