Simulation study of polymer-nanotube hybridization in solution

COLL 373

Willis Martin, martiwe@bc.edu, Wusheng Zhu, zhuwu@bc.edu, and Goran Krilov, goran.krilov@bc.edu. Department of Chemistry, Boston College, 2609 Beacon Str, Chestnut Hill, MA 02467
Complexes of carbon nanotubes with natural and synthetic polymers adsorbed at their surface have received great interest recently. In contrast to covalent functionalization, non-covalent hybridization with polymers has been found to disperse the poorly soluble nanotubes in aqueous and organic solvents without chemically altering their structure. Hence, numerous applications have been suggested for these hybrids, from separation of polydispersed nanotubes to construction of molecular probes, solar cells and superior nanocomposite materials. The mechanisms these processes, including the nature of the polymer-nanotube interactions, are still largely unknown. In this study, we use replica exchange molecular dynamics to investigate the interaction between several types of polymers and carbon nanotubes in various solvents. We report the observed binding modes, binding free energies and electrostatic properties of the hybrids as a function of polymer sequence and nanotube diameter. Finally, we propose several hybrid features that can be utilized for efficient nanotube separation and construction of nanodevices.