Dispersing Single-Walled Carbon Nanotubes with Surfactants:  A Small Angle Neutron Scattering Study

Abstract

We have investigated the dispersion of single-walled carbon nanotubes (SWNTs) in heavy water with the surfactant octyl-phenol-ethoxylate (Triton X-100) using small angle neutron scattering. The results indicate an optimal surfactant concentration for dispersion, which we suggest results from competition between maximization of surfactant adsorption onto SWNT surfaces and a depletion interaction between SWNT bundles mediated by surfactant micelles. The latter effect drives SWNT reaggregation above a critical volume fraction of micelles. These behaviors could be general in dispersing SWNTs using amphiphilic surfactant. The data also reveal significant incoherent scattering from hydrogen in SWNTs, most likely due to acid and water residues from the purification process.

Sonication-assisted dispersion of carbon nanotubes in aqueous solutions of the anionic surfactant SDBS: The role of sonication energy

“…The diameter curves for the dispersed P-SWCNTs overlapped with each other, regardless of the amount of SDBS (Figure 2(a)) or P-SWCNTs (Figure 3(a)) added, indicating that the degree of dispersion of the P-SWCNTs was independent of the amount of surfactant or CNTs added. This was consistent with the observations made by Clark et al [39] and Wang et al [40], which showed that the particle size was not sensitive to surfactant concentration, especially at high surfactant and SWCNT concentrations.…”

Effect of pre and Post-Dispersion on Electro-Thermo-Mechanical Properties of a Graphene Enhanced Epoxy

“…Using simulation in physics allows the number of experiments to be reduced and thus time and cost for development at laboratory and industry scale by linking theory and experimentation [10][11][12][13][14][15][16]. Functionalisation of nanoparticles, when they are dispersed in an epoxy resin, could have two aims: improving the dispersion quality by decreasing the interaction between nanoparticles [17][18][19], and improving the mechanical properties of the composite by improving the interfacial bonding between matrix, nanoparticles and micro-reinforcement [20][21][22][23]. When nanoparticles are dispersed in an epoxy resin, they have a tendency to re-agglomerate and create only weak bonds with the epoxy molecules by Van der Waals interaction.…”

“…sodium dodecyl sulphate (SDS) [18], sodium dodecyl benzenesulfonate (NaDDBS) [41,42]; and (ii) non-ionic e.g. Triton X-100 [17,19].…”

“…The physical adsorption of the chemical group induces less damages onto the particles than a classic functionalisation which makes this chemical modification really attractive for graphene/ epoxy nanocomposites [24]. Only a few studies have been conducted on the treatment of GNP with a surfactant [17,18,42]. However, due to the close structure between CNT and GNP, previous studies made on CNT can be used as a base and inspiration for the functionalisation of GNP.…”

Liquid‐Phase Exfoliation of Nanotubes and Graphene

“…Nanotubes have been dispersed and stabilised with the aid of specific solvents [16][17][18][19][20][21][22][23][24] , acids [25,26] , macromolecules [27][28][29][30] and surfactants [31][32][33][34] as well as through covalent functionalisation strategies [35,36] . Such systems have been characterised by a range of techniques such as atomic force microscopy [37] , infra-red photoluminescence and absorbance spectroscopy [34] , viscometry [25] , small angle neutron scattering [32] to name but a few. These strategies have been extremely successful, resulting in highly exfoliated, well defined and comprehensively characterised systems of dispersed nanotubes.…”