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.

Investigation of Surfactant Type, Dosage and Ultrasonication Temperature Control on Dispersity of Metal-Coated Multi-Walled Carbon Nanotubes

2016 ◽  
Vol 16 (4) ◽  
pp. 4224-4232
Author(s):  
Xiaoning Liang ◽  
Wei Li
Keyword(s):  
Carbon Nanotubes ◽  
Oleic Acid ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Negative Effects ◽  
Ultrasonic Dispersion ◽  
Dispersion Process ◽  
Ultrasonic Assisted ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We studied the dispersity of multi-walled carbon nanotubes (MWNTs) combined with different metallic particles (Ni and Fe). An ultrasonic-assisted water-bath dispersion process was used to disperse the metal-coated MWNTs in different solutions and the dispersity was measured using an ultraviolet-visible spectrophotometer. The dispersity and morphology of the MWNTs were characterized using field-emission scanning electron microscopy (FE-SEM) together with digital image processing technology. Effects of dispersant type (sodium dodecyl benzene sulfonate (SDBS), oleic acid, and polymer (TNEDIS)) and surfactant dosage on the dispersity of the metal-coated MWNTs were investigated under controlled and uncontrolled temperatures and results were compared with those from the untreated MWNTs. The results showed that the negative effects of temperature on the ultrasonic dispersion process could be eliminated through a temperature-controlled system. Moreover, the TNEDIS, SDBS, and oleic acid were arranged in the descending order of the dispersion effect degree. The untreated MWNTs, Ni-coated MWNTs, and Fe-coated MWNTs were arranged in the descending degree of dispersity order. Since the metal coating makes the MWNTs harder and more fragile, the metal-coated MWNTs are more likely to fracture during the ultrasonic dispersion process.

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.

Dispersion of Carbon Nanotubes in Cement-Based Composites and Its Influence on the Piezoresistivities of Composites

2009 ◽  
Author(s):  
Baoguo Han ◽  
Xun Yu ◽  
Jinping Ou
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Cement Mortar ◽  
Sodium Dodecyl ◽  
Impulsive Loading ◽  
Repeated Loading ◽  
Sodium Dodecylbenzene Sulfonate ◽  
Dodecylbenzene Sulfonate ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (NaDDBS) are used as surfactants to improve the dispersion of multi-walled carbon nanotubes (MWNTs) in cement mortar and fabricate piezoresistive carbon-nanotube/cement mortar composite. The piezoresistivity of carbon-nanotube/cement mortar composite with different content levels of MWNTs and different surfactants were explored under repeated loading and impulsive loading. Experimental results indicate that NaDDBS has higher efficiency than SDS for the dispersion of MWNTs in cement mortar. The response of the electrical resistance of carbon-nanotube/cement mortar composite with NaDDBS to external force is more stable and sensitive than that of carbon-nanotube/cement mortar composite with SDS. These findings indicate that the use of NaDDBS is an effective way for improving the dispersion of MWNTs in cement-based composite and fabricating MWNTs filled cement-based composite with stable and strong piezoresistive response.

Polypyrrole with a functionalized multi-walled carbon nanotube hybrid nanocomposite: a new and efficient nitrite sensor

2018 ◽  
Vol 42 (5) ◽  
pp. 3748-3757 ◽  
Author(s):  
Abraham Daniel Arulraj ◽  
Ellairaja Sundaram ◽  
Vairathevar Sivasamy Vasantha ◽  
Bernaurdshaw Neppolian
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Sodium Dodecyl Sulfate ◽  
Conducting Polymers ◽  
Sodium Dodecyl ◽  
Hybrid Nanocomposite ◽  
Multi Walled Carbon Nanotube ◽  
Dodecyl Sulfate ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This study mainly focuses on the electrochemical-assisted synthesis of conducting polymers such as polypyrrole (PPy) with sodium dodecyl sulfate (SDS) as a surfactant and supported with functionalized multi-walled carbon nanotubes (f-MWCNTs).

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