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

 

M221Royal College of ScienceSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Clancy:2018:10.1021/acs.langmuir.8b03144,
author = {Clancy, AJ and Leese, HS and Rubio, Carrero N and Buckley, DJ and Greenfield, JL and Shaffer, MSP},
doi = {10.1021/acs.langmuir.8b03144},
journal = {Langmuir},
pages = {15396--15402},
title = {Depleting depletion: maintaining single-walled carbon nanotube dispersions after graft-to polymer functionalization},
url = {http://dx.doi.org/10.1021/acs.langmuir.8b03144},
volume = {34},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Grafting polymers onto single-walled carbon nanotubes (SWCNTs) usefully alters properties but does not typically yield stable, solvated species directly. Despite the expectation of steric stabilization, a damaging (re)dispersion step is usually necessary. Here, poly(vinyl acetate)s (PVAc) of varying molecular weights are grafted to individualized, reduced SWCNTs at different concentrations to examine the extent of reaction and degree of solvation. The use of higher polymer concentrations leads to an increase in grafting ratio (weight fraction of grafted polymer relative to the SWCNT framework), approaching the limit of random sequentially adsorbed Flory ‘mushrooms’ on the surface. However, at higher polymer concentrations, a larger percentage of SWCNTs precipitate during the reaction; an effect which is more significant for larger weight polymers. The precipitation is attributed to depletion interactions generated by ungrafted homopolymer overcoming Coulombic repulsion of adjacent like-charged SWCNTs; a simple model is proposed. Larger polymers and greater degrees of functionalization favor stable solvation, but larger and more concentrated homopolymers increase depletion aggregation. By using low concentrations (25 μM) of larger molecular weight PVAc (10 kDa), up to 65% of grafted SWCNTs were retained in solution (at 65 μg mL-1) directly after the reaction.
AU  - Clancy,AJ
AU  - Leese,HS
AU  - Rubio,Carrero N
AU  - Buckley,DJ
AU  - Greenfield,JL
AU  - Shaffer,MSP
DO  - 10.1021/acs.langmuir.8b03144
EP  - 15402
PY  - 2018///
SN  - 0743-7463
SP  - 15396
TI  - Depleting depletion: maintaining single-walled carbon nanotube dispersions after graft-to polymer functionalization
T2  - Langmuir
UR  - http://dx.doi.org/10.1021/acs.langmuir.8b03144
UR  - http://hdl.handle.net/10044/1/66368
VL  - 34
ER  -
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