Identification of surfactants aggregates on graphitic surface of carbon nanotubes

Abstract

There are a relatively large number of studies on surfactants facilitates the dispersion of multi-walled carbon nanotubes (MWCNTs), however reports for both orientation and size aggregation of surfactants on MWCNTs are scarcely described. In this study, we demonstrate the visualization of the surfactants aggregates onto MWCNTs using atomic force microscopic (AFM) and field emission electron scanning microscopy (FESEM) to provide information on the orientation and the grains size of surfactants-MWCNTs aggregates. MWCNTs treated with surfactants of different charges, namely sodium dodecyl sulphate (SDS), the anionic, cetyltrimethyl ammonium bromide (CTAB), the cationic and polysorbate 80 (Tween-80), the non-ionic, displayed substantial pattern of surfactant-MWCNTs surface contours. Raman spectroscopy analysis has been presented in order to report the characteristic of defective MWCNTs graphitize structure upon non-covalent adsorption of respective surfactants.

Stabilization of Carbon Nanotubes and Graphene by Tween-80: Mechanistic Insights from Spectroscopic and Simulation Studies

“…It is expected that a conformation similar to that observed in micelles also exists in the presence of CNPs, ,, whereby the hydrophobic fatty acid chain interacts with the CNP surface, while hydrophilic sorbitan and PEO moieties extend into the aqueous phase. Such a conformation has also been demonstrated by MD simulations and supported by atomic force microscopy . Furthermore, FTIR analysis also revealed a similar mechanism of interaction in the preceding section.…”

“…Microscopic examination of multi-walled CNTs (MWCNTs) revealed complete and uniform coverage of the CNT surface with Tween-80 molecules. 17 Field emission electron microscopy analysis revealed a uniform surface coverage of MWCNTs by Tween-80, while atomic force microscopy revealed that Tween-80 aggregates on the MWCNT surface appeared as grains, which were at least 251 nm broad and approximately 6 nm high. Based on the microscopy analysis, the authors proposed that the surfactant Tween-80 molecules appeared to interact with the MWCNT structure through the lipid tail, while the hydrophilic head appears to remain in the aqueous environment.…”

“…Polyoxyethylene sorbitan monooleate, commonly known as Tween-80, is one of the most commonly employed polyethoxylate surfactants. ,,, Despite its frequent use in dispersing NPs, the mechanism of stabilization by this surfactant has been poorly studied. Microscopic examination of multi-walled CNTs (MWCNTs) revealed complete and uniform coverage of the CNT surface with Tween-80 molecules . Field emission electron microscopy analysis revealed a uniform surface coverage of MWCNTs by Tween-80, while atomic force microscopy revealed that Tween-80 aggregates on the MWCNT surface appeared as grains, which were at least 251 nm broad and approximately 6 nm high.…”

Selective Chemistry-Based Separation of Semiconducting Single-Walled Carbon Nanotubes and Alignment of the Nanotube Array Network under Electric Field for Field-Effect Transistor Applications

“…The length and density of s-SWCNTs before and after the electrical field alignment were determined through FE-SEM. For this purpose, FE-SEM micrographs were analyzed using the Java-based image processing program known as Image J software …”

“…For this purpose, FE-SEM micrographs were analyzed using the Java-based image processing program known as Image J software. 65 4.4. Alignment of s-SWCNTs.…”