SWCNTs Dispersion via an Amphiphilic Polymer

Single-walled carbon nanotubes (SWCNTs) exhibit excellent mechanical, electrical, thermal, and optical properties. They are considered promising materials for a number of applications for which, however, individual SWCNTs are required instead of the complex mixture of metallic and semiconducting species obtained upon their preparation. The establishment of dispersion and separation protocols for SWCNTs is therefore of capital importance to enable their effective exploitation. There are many different approaches for the dispersion of SWCNTs, which typically entail non-covalent interactions between amphiphilic molecules and the wall of the tubes in aqueous solution. Common surfactants (e.g. SDS, SC, SDBS) are typically used for this purpose. We report an effective strategy for the preparation of single-walled carbon nanotube dispersions, based on the use of an amphiphilic polymer (PHMPMA-b-PSt) and compare it with a standard surfactant (SDBS) and another polymer lacking pendant phenyl groups (PHMPMA-b-PMMA). The polymers used in this work are new and obtained by post-polymerization treatments of RAFT synthesized poly(glycidyl methacrylate) (PGMA). We found that the polymer can form micelles around the SWCNTs through its hydrophobic chain, whilst the hydrophilic part prompts dispersion in water. The excellent dispersion capability of our polymer is demonstrated by electronic absorption spectra, photoluminescence mapping of the SWCNTs (Figure 1) and AFM studies. 1 H. Wang, Curr. Opin. Colloid Interface Sci., 2009, 14, 364-371. 2 M. Benaglia, A. Alberti, L. Giorgini, F. Magnoni and S. Tozzi, Polym. Chem., 2013, 4, 124-132.