Selective Dispersion of Large-Diameter Semiconducting Single-Walled Carbon Nanotubes with Pyridine-Containing Copolymers

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 10; no. 2; pp. 360 - 367
• Main Authors: Berton, Nicolas, Lemasson, Fabien, Poschlad, Angela, Meded, Velimir, Tristram, Frank, Wenzel, Wolfgang, Hennrich, Frank, Kappes, Manfred M., Mayor, Marcel
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 29.01.2014; Wiley Subscription Services, Inc
• Subjects: Copolymers; fluorene-pyridine copolymer; Nanotechnology; NIR photoluminescence; polymer wrapping; selective dispersing agent; single-walled carbon nanotubes; fluorene-pyridine copolymer; NIR photoluminescence; polymer wrapping; selective dispersing agent; single-walled carbon nanotubes
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201301295

The purity of single‐walled carbon nanotubes (SWNTs) is a key parameter for their integration in electronic, optoelectronic and photonic devices. Samples of pristine SWNTs are inhomogeneous in terms of electric behavior and diameter and contain a variety of amorphous carbon and catalyst residues. To obtain high performance devices, purification of SWNTs is required. Conjugated polymers have emerged as efficient solubilizing and sorting agents for small diameter SWNTs (HiPco tubes, 0.7 nm<Ø<1.1 nm). Nevertheless, reports on polymers able to efficiently sort large diameter SWNTs with Ø>1.1 nm are lacking. Several pyridine‐containing copolymers were synthesized for this purpose and showed efficient and selective extraction of semiconducting large diameter SWNTs (PLV tubes, Ø>1.1 nm). High concentration and high purity suspensions are obtained without the use of ultracentrifugation, which gives an up‐scaling potential of the method. The emission wavelength is in near infrared region around 1550 nm and fits with broadly used telecommunication wavelength window. The processes taking place at the interface were simulated by a newly designed hybrid coarse‐grain model combining density functional theory and geometrical calculation to yield insights into the wrapping processes with an unprecedented level of details for such large diameter SWNTs. Large‐diameter semiconducting single‐walled carbon nanotubes are efficiently and selectively extracted in organic media via polymer wrapping when using a fluorene–pyridine copolymer as dispersing agent. High concentration and high purity suspensions are obtained without the use of ultracentrifugation. The near infrared emission wavelength around 1550 nm fits with broadly used telecommunication wavelength window.