Functionalization of Single-Walled Carbon Nanotubes with End-Capped Polystyrene via a Single-Step Diels-Alder Cycloaddition

Maria-Malvina Stathouraki; Christos Pantazidis; Emmanouil Mygiakis; Apostolos Avgeropoulos; Georgios Sakellariou

doi:10.3390/polym13071169

Functionalization of Single-Walled Carbon Nanotubes with End-Capped Polystyrene via a Single-Step Diels-Alder Cycloaddition

Polymers (Basel). 2021 Apr 6;13(7):1169. doi: 10.3390/polym13071169.

Authors

Maria-Malvina Stathouraki¹, Christos Pantazidis¹, Emmanouil Mygiakis¹, Apostolos Avgeropoulos², Georgios Sakellariou¹

Affiliations

¹ Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece.
² Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece.

Abstract

A facile, single-step, [4+2] Diels-Alder cycloaddition reaction for the surface functionalization of single-walled carbon nanotubes (SWNTs) with end-capped polystyrene chains is presented. The thermal cycloaddition reaction took place at high temperature (~230 °C) without any catalyst between the sp² network of carbon nanotubes, which acted as dienophile, and the diphenylethylene cyclobutene (DPE-CB) terminal group of the polystyrene chain. Anionic polymerization was employed for the synthesis of the polystyrene macromolecule, and successful and quantitative end-capping reaction with the DPE-CB molecule was confirmed by matrix-assisted laser desorption/ionization time of flight mass spectroscopy. Thermogravimetric analysis revealed the wt % of the grafted macromolecule on the CNT surface as well as the grafting density of the polymer chains on the SWNTs (0.027 chains nm^-2). Direct evidence for the surface functionalization and the presence of thin polystyrene film was obtained by transmission electron microscopy (TEM) and by atomic force microscopy (AFM).

Keywords: [4+2] Diels–Alder cycloaddition; anionic polymerization; single-walled carbon nanotubes; surface functionalization.