| Autor: |
Raja PMV; Department of Chemistry, Rice University, Houston, TX 77005, USA. arb@rice.edu., Esquenazi GL, Wright KD, Gowenlock CE, Brinson BE, Alexander S, Jones DR, Gangoli VS, Barron AR |
| Jazyk: |
angličtina |
| Zdroj: |
Nanoscale [Nanoscale] 2018 Nov 07; Vol. 10 (41), pp. 19628-19637. Date of Electronic Publication: 2018 Oct 16. |
| DOI: |
10.1039/c8nr06485g |
| Abstrakt: |
The electromigration behaviour of raw and acid purified single walled carbon nanotubes (SWCNTs) in dilute aqueous systems (0.0034 mg mL -1 ), in the absence of surfactant, with the addition of either 0.85 M acetic acid or 0.1 M CuSO 4 , was evaluated using a 2-inch copper cathode and either a 2-inch copper or 0.5-inch platinum anode. The results showed that the electromigration of raw SWCNTs (with a high catalyst residue) in the presence of CuSO 4 resulted in the formation of a Cu-SWCNT composite material at the cathode. In contrast, acid purified SWCNTs were observed to diffuse to a copper anode, creating fibrillated agglomerates with "rice-grain"-like morphologies. Upon acidification with acetic acid (or addition of CuSO 4 ) the direction of electromigration reversed towards the cathode as a result of coordination of Cu 2+ to the functional groups on the SWCNT overcoming the inherent negative charge of the acid purified SWCNTs. The result was the co-deposition of SWCNTs and Cu metal on the cathode. Addition of 0.005 M EDTA sequesters some of the Cu 2+ and resulted in the separation of metal decorated SWCNTs to the cathode and un-decorated SWCNTs to the anode. The resulting SWCNT and Cu/SWCNT deposits were characterized by Raman spectroscopy, XPS, SEM, EDS, and TEM. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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