skip to primary navigationskip to content

Chirality-independent characteristic crystal length in carbon nanotube textiles measured by Raman spectroscopy

last modified Jan 28, 2017 11:04 PM
A new paper by John S. Bulmer, Thurid S. Gspann, Jon S. Barnard and James A. Elliott is published in Carbon.

Raman spectroscopy's D:G ratio is a well-known indicator of graphitic crystallinity in single-wall carbon nanotubes (SWCNTs) with widespread qualitative application to macroscopic CNT assemblies. Here, we show how the D:G ratio yields quantitative characteristic crystal length features that is remarkably independent of SWCNT chirality when purified SWCNTs are in a high density, heavily bundled textile form. Purified, unaligned, SWCNT films of enriched length distributions and controlled chirality responded in ways consistent with power law behaviour, where the D:G ratio is proportional to the fourth power of excitation wavelength, inversely proportional to SWCNT length, and fits to a master curve independent of electronic species concentration. This behaviour, matching the established response of graphite and graphene, unexpectedly persists despite complications from chirality-dependent resonances unique to SWCNTs. We also show that textiles comprising of aligned, long length CNTs defy these simple power laws until defective multiwall CNTs and impurities are removed post-process, and only if sample heating under the Raman laser is minimized. Adjusting the Raman laser beam diameter up to 6 mm, which is well beyond the average CNT length, we propose that the CNT textile's characteristic crystal length is the CNT length or, with point defects, the distance between point defects.

DOI:10.1016/j.carbon.2017.01.044

RSS Feed Latest news

Research Associate (Fixed Term) - 2 positions

May 08, 2017

The Macromolecular Materials Laboratory is seeking two Research Associates to work on the production, characterisation and molecular modelling of polymeric membranes incorporating carbon nanotubes (CNTs) for desalination applications.

Research Assistant (part-time)

May 02, 2017

The Macromolecular Materials Laboratory is looking for a capable and dedicated Research Assistant (Grade 5) to contribute to their work on nanotube characterisation.

Congratulations to Dr Chunlei Pei

Mar 31, 2017

Dr Chunlei Pei wins a Young Researcher Prize for an oral presentation at the UK Particle Technology forum held at University of Birmingham on 29th March 2017.

MML Fajita Lunch

Feb 20, 2017

MML group had a pleasant Fajita Lunch on Friday 17th February 2017. We wish everyone has a fruitful and successful new year.

Multi-scale modelling of carbon nanotube reinforced crosslinked interfaces

Jan 28, 2017

A new paper by James A. Elliott and his Turkish collaborators Elif Ozden-Yenigun and Canan Atilgan is published in Computational Materials Science

View all news