scholarly journals Change in chirality of semiconducting single-walled carbon nanotubes can overcome anionic surfactant stabilisation: a systematic study of aggregation kinetics

2015 ◽  
Vol 12 (6) ◽  
pp. 652 ◽  
Author(s):  
Iftheker A. Khan ◽  
Joseph R. V. Flora ◽  
A. R. M. Nabiul Afrooz ◽  
Nirupam Aich ◽  
P. Ariette Schierz ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Anionic Surfactants ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Single Walled Carbon Nanotubes ◽  
Sodium Deoxycholate ◽  
Single Walled Carbon ◽  
Aggregation Behaviour ◽  
Dodecyl Benzene Sulfonate ◽  
Walled Carbon Nanotubes

Environmental context Chirally enriched semiconducting single-walled carbon nanotubes (SWNTs) are some of the most utilised nanomaterials. Although chirality of SWNTs is known to influence their electronic properties and interfacial interaction, the interplay between chirality and surfactant structure in SWNT stability is not well understood. This study investigates these interactions, providing data to better assess the environmental fate of SWNTs. Abstract Single-walled carbon nanotubes’ (SWNT) effectiveness in applications is enhanced by debundling or stabilisation. Anionic surfactants are known to effectively stabilise SWNTs. However, the role of specific chirality on surfactant-stabilised SWNT aggregation has not been studied to date. The aggregation behaviour of chirally enriched (6,5) and (7,6) semiconducting SWNTs, functionalised with three anionic surfactants – sodium dodecyl sulfate, sodium dodecyl benzene sulfonate and sodium deoxycholate – was evaluated with time-resolved dynamic light scattering. A wide range of mono- (NaCl) and divalent (CaCl2) electrolytes as well as a 2.5mg total organic carbon (TOC) L–1 Suwannee River humic acid were used as background chemistry. Overall, sodium dodecyl benzene sulfonate showed the most effectiveness in stabilising SWNTs, followed by sodium deoxycholate and sodium dodecyl sulfate. However, the larger diameter (7,6) chirality tubes (compared to (6,5) diameter), compromised the surfactant stability due to enhanced van der Waals interaction. The presence of divalent electrolytes overshadowed the chirality effects and resulted in similar aggregation behaviour for both the SWNT samples. Molecular modelling results elucidated key differences in surfactant conformation on SWNT surfaces and identified interaction energy changes between the two chiralities to delineate aggregation mechanisms. The stability of SWNTs increased in the presence of Suwannee River humic acid under 10mM monovalent and mixed-electrolyte conditions. The results suggest that change in chirality can overcome surfactant stabilisation of semiconducting SWNTs. SWNT stability can also be strongly influenced by the anionic surfactant structure.

METHODS FOR DISPERSION AND ALIGNMENT OF SINGLE-WALLED CARBON NANOTUBES AND EFFECTS ON THEIR STRUCTURAL AND ELECTRONIC PROPERTIES

2006 ◽  
Vol 05 (04n05) ◽  
pp. 407-411
Author(s):  
JUN JIAO ◽  
LIFENG DONG ◽  
VACHARA CHIRAYOS ◽  
JOCELYN BUSH ◽  
JAMES HEDBERG
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Sodium Dodecyl ◽  
Single Walled Carbon Nanotubes ◽  
Dielectric Medium ◽  
High Yield ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
The Individual ◽  
Walled Carbon Nanotubes

Two effective methods for dispersion and alignment of single-walled carbon nanotubes (SWCNTs) were developed. One is the floating-potential dielectrophoresis (FPD) method, which can achieve the alignment of individual SWCNTs between two electrodes with high yield (more than 30%) and high repeatability. The second is the gas blow method. Using the shear forces associated with a rapidly moving fluid, SWCNTs were positioned in a direction corresponding to the flow vector of the fluid. This technique shows great potential for scaling up the displacement of SWCNTs with controlled orientations. Various dispersion agents including ethanol, dichlorobenzene, sodium dodecyl sulfate (SDS) and DNA were investigated with these two methods. It was found that SDS was the most effective dielectric medium used for FPD dispersion and alignment of SWCNTs. The result of electric measurement for the individual SWCNTs aligned between two electrodes suggests that, using the FPD method, both metallic and semiconducting SWCNTs could be aligned between the electrodes. The individual SWCNT resistances measured range from 20 KΩ to 5 MΩ suggesting a high contact resistance between an aligned SWCNT and metal electrodes. High resolution transmission electron microscopy (TEM) and scanning electron microscopy (SEM) characterization reveal DNA molecules wrapped around the SWNCTs after the dispersion process which may affect the intrinsic properties of SWCNTs.

The Evaluation of Individual Dispersion of Single-Walled Carbon Nanotubes Using Absorption and Fluorescence Spectroscopic Techniques

2007 ◽  
Vol 7 (11) ◽  
pp. 3727-3730
Author(s):  
Dokyung Yoon ◽  
Sun-Jung Kang ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
Seunghyun Baik
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Media ◽  
Sodium Dodecyl ◽  
Single Walled Carbon Nanotubes ◽  
Spectroscopic Techniques ◽  
Single Walled Carbon ◽  
Dispersion State ◽  
Semiconducting Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Nanotube Chirality

We have investigated the degree of dispersion of single-walled carbon nanotubes (SWNTs) in solution using laser spectroscopic techniques. SWNTs were suspended in aqueous media using a sodium dodecyl sulfate (SDS) surfactant. SWNTs with different dispersion states were prepared by controlling the intensity and duration of sonication and centrifugation. The absorption and fluorescence spectroscopic techniques were employed to characterize the different dispersion state of the prepared samples. Nanotube suspensions with better dispersion showed higher fluorescence and sharper absorption peaks. The fluorescence data were characterized as a function of the nanotube chirality, and absorption peak shifts were analyzed depending on the first and second van Hove singularities (vHs) of semiconducting nanotubes.

Organic Soft Template Method to Arrange Palladium Nanoparticles on Single-Walled Carbon Nanotubes

2011 ◽  
Vol 284-286 ◽  
pp. 750-754
Author(s):  
Zhenquan Tan ◽  
Hiroya Abe ◽  
Mikio Naito ◽  
Satoshi Ohara
Keyword(s):  
Carbon Nanotubes ◽  
Self Assembly ◽  
Sodium Dodecyl ◽  
Single Walled Carbon Nanotubes ◽  
Pd Nanoparticles ◽  
Soft Template ◽  
Chemical Route ◽  
Single Walled Carbon ◽  
Adsorption Sites ◽  
Walled Carbon Nanotubes

A facile solution-chemical route was reported to deposit and arrange palladium (Pd) nanoparticles on single-walled carbon nanotubes (SWCNTs) using sodium dodecyl sulfate (SDS) as an organic soft template. SDS was previously formed supramolecular self-assembly on the walls of SWCNTs, which may act as adsorption sites of Pd (II) ions on SWCNTs. The Pd nanoparticles reduced by photo-reduction and formed one-dimensionally ordered arrangement on the surface of SWCNTs with a veriety of helices and tilted angles. Pd nanoparticles have an average size of 3 nm. The structure (distance, helix and tilted angle) of the ordered arrangements were determined by the supramolecular self-assembly of SDS wrapped on SWCNTs.

Removal of Multi-Walled Carbon Nanotubes From Contaminated Surfaces With Microscale Topological Features

2014 ◽  
Author(s):  
Zahra Karimi ◽  
Paul Su ◽  
Babak Haghpanah ◽  
William W. Doerr ◽  
Louis A. Gritzo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Liquid Solution ◽  
Silicon Wafers ◽  
Etching Time ◽  
Topological Features ◽  
Multi Walled Carbon Nanotubes ◽  
Dodecyl Benzene Sulfonate ◽  
Walled Carbon Nanotubes

Experiments were performed to examine the ability of surfactants to remove multi-walled carbon nanotubes (MWCNTs) from silicon wafers with nano and micro scaled features. Well-defined microscale topological features on silicon wafers were induced using photo lithography and plasma etching. The etching time was varied to create variation in topological features with the size and height of ∼ 8±1 μm, and ∼2±1 μm, respectively. MWCNTs in the form of pristine liquid solution were deposited on the surface of silicon wafers using the spin coating process. During cleaning, the contaminated surfaces were first sprayed with one of the two surfactants, sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS), or water. MWCNTs were wiped off using a wiping mechanism. The area density of the MWCNTs was quantified prior to and after their removal using scanning electron microscopy (SEM) and post-image processing. The results show decreasing removal efficiency for all the surfactants as the topological features on the wafers deepen through increasing the etching time. Surfactants show better decontamination efficiency compared with water.

The Evaluation of Individual Dispersion of Single-Walled Carbon Nanotubes Using Absorption and Fluorescence Spectroscopic Techniques

2007 ◽  
Vol 7 (11) ◽  
pp. 3727-3730 ◽  
Author(s):  
Dokyung Yoon ◽  
Sun-Jung Kang ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
Seunghyun Baik
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Media ◽  
Sodium Dodecyl ◽  
Single Walled Carbon Nanotubes ◽  
Spectroscopic Techniques ◽  
Single Walled Carbon ◽  
Dispersion State ◽  
Semiconducting Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Nanotube Chirality

We have investigated the degree of dispersion of single-walled carbon nanotubes (SWNTs) in solution using laser spectroscopic techniques. SWNTs were suspended in aqueous media using a sodium dodecyl sulfate (SDS) surfactant. SWNTs with different dispersion states were prepared by controlling the intensity and duration of sonication and centrifugation. The absorption and fluorescence spectroscopic techniques were employed to characterize the different dispersion state of the prepared samples. Nanotube suspensions with better dispersion showed higher fluorescence and sharper absorption peaks. The fluorescence data were characterized as a function of the nanotube chirality, and absorption peak shifts were analyzed depending on the first and second van Hove singularities (vHs) of semiconducting nanotubes.

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