Phthalimide containing donor-acceptor polymers for effective dispersion of single-walled carbon nanotubes

Baris Yilmaz, Josiah Bjorgaard, Zhenghuan Lin, Muhammet E. Köse

Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108, USA

TUBITAK Marmara Research Center, Gebze, Kocaeli, 41470 Türkiye

Abstract: Single-walled carbon nanotubes have been dispersed by novel phthalimide containing donor-acceptor type copolymers in organic media. Brominated phthalimide comonomer has been copolymerized with several electron rich structures using Suzuki and Stille coupling reactions. Carbon nanotube dispersion capability of the resultant polymers has been assessed by exploiting the non-covalent interaction of nanotube surface with the pi-system of conjugated backbone of polymers. Four polymers have been found to be good candidates for individually dispersing nanotubes in solution. In order to identify the dispersed nanotube species, 2D excitation-emission map and Raman spectroscopy have been performed. Molecular dynamics modelling has been utilized to reveal the binding energies of dispersants with the nanotube surface and the simulation results have been compared with the experimental findings. Both experimental and theoretical results imply the presence of a complex mechanism that governs the extent of dispersion capacity and selectivity of each conjugated polymeric dispersant in solubilizing carbon nanotubes.

Keywords: Phthalimide polymers, carbon nanotubes, separation, Raman spectroscopy, molecular dynamics simulations. © 2015 ACG Publications. All rights reserved.