Imperial College London
Alternate

Prof Milo Shaffer

Faculty of Natural Sciences, Department of Chemistry

Professor of Materials Chemistry
 
 
 
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Contact

 

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

 
 
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Assistant

 

Mr John Murrell +44 (0)20 7594 2845

 
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Location

 

401BMolecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Brandley:2018:10.1016/j.carbon.2018.04.063,
author = {Brandley, E and Greenhalgh, E and Shaffer, M and Li, Q},
doi = {10.1016/j.carbon.2018.04.063},
journal = {Carbon},
pages = {78--87},
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},
volume = {137},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A novel method of applying a two-dimensional Fourier transform (2D-FFT) to SEM was developed to map the CNT orientation in pre-formed arrays. Local 2D-FFTs were integrated azimuthally to determine an orientation distribution function and the associated Herman parameter. 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, the method was specifically developed to study CNT veils, a system in which orientation critically controls mechanical properties. Using this system as a model, key parameters for the 2D-FFT analysis were optimised, including magnification and domain size; a model set of CNT veils were pre-strained to 5%, 10% and 15%, to vary the alignment degree. The algorithm confirmed a narrower orientation distribution function and increasing Herman parameter, with increasing pre-strain.To validate the algorithm, the local orientation was compared to that derived from a common polarised Raman spectroscopy. Orientation maps of the Herman parameter, derived by both methods, showed good agreement. Quantitatively, the mean Herman parameter calculated using the polarised Raman spectroscopy was 0.42±0.004 compared to 0.32±0.002 for the 2D-FFT method, with a correlation coefficient of 0.73. Possible reasons for the modest and systematic discrepancy were discussed.
AU  - Brandley,E
AU  - Greenhalgh,E
AU  - Shaffer,M
AU  - Li,Q
DO  - 10.1016/j.carbon.2018.04.063
EP  - 87
PY  - 2018///
SN  - 0008-6223
SP  - 78
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  - https://www.sciencedirect.com/science/article/pii/S000862231830424X
UR  - http://hdl.handle.net/10044/1/59253
VL  - 137
ER  -
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