Interactions between polymers and single-walled boron nitride nanotubes: a molecular dynamics simulation approach

In this work, we used a molecular dynamics (MD) simulation approach to investigate the interfacial binding of boron nitride nanotubes (BNNTs) with poly[m-phenylenevinylene-co-(2,5-dioctyloxy-p-phenylenevinylene)] (PmPV), polystyrene (PS), and polythiophene (PT). Quantum partial charges of BNNT-polymer composites were determined by density functional theory (DFT) calculations and then included in MD simulations. The interaction energy between nanotubes and polymer molecules was computed, and the morphology of polymers stacked onto the surface of the nanotubes was investigated based on the dihedral angle (θ). Our results confirm that the interaction energy is strongly influenced by the specific monomer structure of polymer and nanotube radius, but the influence of temperature is likely negligible. Among the investigated polymers, PT possesses the strongest adhesion to the BNNTs, followed by PmPV and PS. Moreover, the comparison of our results for BNNT-polymer composities with those of the similar carbon nanotube (CNT)-polymer composites reveals that the BNNT-polymer interactions are much stronger, which is the most important result of this work. This finding is also in good agreement with recent experimental observations. The higher values of interaction energy of BNNT-polymer composites suggest that the BNNTs could be more efficient nanofillers than the CNTs for nanocomposite reinforcement applications.