van der Waals layer-by-layer construction of a carbon nanotube 2D network
The acid-treated single-walled carbon nanotubes (SWCNTs) dispersed in water are only kinetically stable with electrostatic double layer repulsions just balancing against van der Waals (VDW) attractions. Introducing any external factor to disturb this balance causes immediate coagulation of SWCNTs. H...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1999. - 21(2005), 24 vom: 22. Nov., Seite 11490-4 |
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| Format: | Aufsatz |
| Sprache: | English |
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2005
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | The acid-treated single-walled carbon nanotubes (SWCNTs) dispersed in water are only kinetically stable with electrostatic double layer repulsions just balancing against van der Waals (VDW) attractions. Introducing any external factor to disturb this balance causes immediate coagulation of SWCNTs. Here, an amine-covered flat substrate was immersed in the dispersion to initiate adsorption of SWCNTs onto the substrate surface. By repeating an adsorption-rinse-dry cycle, it was possible to deposit SWCNT bundles in a layer-by-layer fashion and to develop a 2D network consisting only of SWCNTs that are held by VDW interaction. We show that (1) adsorbed solution-grown aggregates are not relevant for the network connectivity, (2) 2D percolation takes place at very low surface coverage, (3) the electrical resistivity follows a power law against the layering cycles, (4) not only the adsorbed amount but also the added amount per layering cycle increases linearly with the SWCNT concentration, and (5) after the adsorption is initiated by amines, VDW attraction takes over for subsequent adsorption, with the consequence that the newly adsorbed SWCNTs are used to thicken each arm of the network rather than to cover more free surfaces |
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| Beschreibung: | Date Completed 05.04.2007 Date Revised 15.11.2005 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |