Imperial College London

Prof Milo Shaffer

Faculty of Natural SciencesDepartment of Chemistry

Professor of Materials Chemistry
 
 
 
//

Contact

 

+44 (0)20 7594 5825m.shaffer Website

 
 
//

Assistant

 

Mr John Murrell +44 (0)20 7594 2845

 
//

Location

 

M221Royal College of ScienceSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Li:10.1016/j.carbon.2018.04.063,
author = {Li, Q and Brandley, E and Shaffer, M and Greenhalgh, E},
doi = {10.1016/j.carbon.2018.04.063},
journal = {Carbon},
title = {Mapping carbon nanotube orientation by fast fourier transform of scanning electron micrographs},
url = {http://dx.doi.org/10.1016/j.carbon.2018.04.063},
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - A novel method of applying a two-dimensional Fourier transform (2D-FFT) to SEM wasdeveloped to map the CNT orientation in pre-formed arrays. Local 2D-FFTs were integratedazimuthally to determine an orientation distribution function and the associated Hermanparameter. This approach provides data rapidly and over a wide range of lengthscales.Although likely to be applicable to a wide range of anisotropic nanoscale structures, themethod was specifically developed to study CNT veils, a system in which orientationcritically controls mechanical properties. Using this system as a model, key parameters forthe 2D-FFT analysis were optimised, including magnification and domain size; a model setof CNT veils were pre-strained to 5%, 10% and 15%, to vary the alignment degree. Thealgorithm confirmed a narrower orientation distribution function and increasing Hermanparameter, with increasing pre-strain.To validate the algorithm, the local orientation was compared to that derived from a commonpolarised Raman spectroscopy. Orientation maps of the Herman parameter, derived by bothmethods, showed good agreement. Quantitatively, the mean Herman parameter calculatedusing the polarised Raman spectroscopy was 0.42±0.004 compared to 0.32±0.002 for the 2DFFTmethod, with a correlation coefficient of 0.73. Possible reasons for the modest andsystematic discrepancy were discussed.
AU - Li,Q
AU - Brandley,E
AU - Shaffer,M
AU - Greenhalgh,E
DO - 10.1016/j.carbon.2018.04.063
SN - 0008-6223
TI - Mapping carbon nanotube orientation by fast fourier transform of scanning electron micrographs
T2 - Carbon
UR - http://dx.doi.org/10.1016/j.carbon.2018.04.063
UR - http://hdl.handle.net/10044/1/59253
ER -