Rational Concept To Recognize/Extract Single-Walled Carbon Nanotubes with a Specific Chirality

Abstract

Single-walled carbon nanotubes (SWNTs) have remarkable and unique electronic, mechanical, and thermal properties, which are closely related to their chiralities; thus, the chirality-selective recognition/extraction of the SWNTs is one of the central issues in nanotube science. However, any rational materials design enabling one to efficiently extract/solubilize pure SWNT with a desired chirality has yet not been demonstrated. Herein we report that certain chiral polyfluorene copolymers can well-recognize SWNTs with a certain chirality preferentially, leading to solubilization of specific chiral SWNTs. The chiral copolymers were prepared by the Ni(0)-catalyzed Yamamoto coupling reaction of 2,7-dibromo-9,9-di-n-decylfluorene and 2,7-dibromo-9,9-bis[(S)-(+)-2-methylbutyl]fluorene comonomers. The selectivity of the SWNT chirality was mainly determined by the relative fraction of the achiral and chiral side groups. By a molecular mechanics simulation, the cooperative interaction between the fluorene moiety, alkyl side chain, and graphene wall were responsible for the recognition/dissolution ability of SWNT chirality. This is a first example describing the rational design and synthesis of novel fluorene-based copolymers toward the recognition/extraction of targeted (n, m) chirality of the SWNTs.

Semiconducting single-walled carbon nanotubes sorting with a removable solubilizer based on dynamic supramolecular coordination chemistry

“…where E complex , E SWNT and E CP-M are the energies of the SWNT/ CP-M complexes, SWNT and CP-M, respectively 32,59,60 . The results are summarized in Table 1 for the calculated potential and stabilizing energy of the CP-Co and CP-Zn systems, respectively.…”

“…In order to preserve the intrinsic SWNT properties, the latter method has an advantage over the former one. Recently, various methods for the separation of sem-and met-SWNTs including wrapping by SWNT solubilizers, such as DNAs 20,21 and p-conjugated or non-conjugated copolymers 11,[22][23][24] , density gradient ultracentrifugation 25,26 and gel chromatography techniques 12,14,[27][28][29][30][31][32][33][34][35][36][37][38][39] , have been reported. However, the reported techniques are rather complex and the efficiency is not very high.…”

“…We have previously demonstrated a rational method for the selective extraction of a specific chirality of the sem-(n,m) SWNTs using a series of systematically designed fluorene-based copolymers [32][33][34] . Moreover, we revealed that the PFO copolymers with a bulky optically active moiety could separate the right-and left-handed sem-SWNTs 35 .…”

Thickness-dependent thermoelectric power factor of polymer-functionalized semiconducting carbon nanotube thin films

“…Among various methods, the separation of high-performance s-SWNTs was achieved using conjugated polymers as an extractant [5]. This technique has been further developed so that fluorene copolymers with various main and side chains, enable the selective separation of specific-diameter s-SWNTs [21]. The technical background above has recently been applied in the investigation of thermoelectric transport.…”

The structure of nanocomposite 1D cationic conductor crystal@SWNT

“…Harris, 2009). At present, no efficient methods for production of SWNTs with a predefined chirality have thus far been developed (Li et al, 2007;Zheng & Semke, 2007;Ozawa et al, 2011). In this connection, the search for desirable modification of electronic structure of SWNTs is important (Saito et al, 1993;Corio et al, 2004).…”