Optimization Conditions for Single-Walled Carbon Nanotubes Dispersion

Abstract

<span>The sonication-driven dispersion of single-walled carbon nanotubes<span> (SWCNTs) </span></a>in aqueous surfactant solution has been monitored by UV-vis-NIR spectroscopy and scanning electron microscopy. Dispersion of SWCNTs experiments reveal that the maximum concentration of dispersed SWCNTs corresponds to the maximum UV-vis-NIR absorbance of the solution. With higher surfactant concentration the dispersion rate of SWCNTs increases and low temperature sonication is required to achieve maximum dispersion. Dispersion of higher SWCNT concentrations requires longer sonication time. For effective dispersion the optimal concentration of surfactant is 1.5 wt%, the concentration of SWCNTs that can be homogeneously dispersed in aqueous solution is about 0.4</span><span> </span><span>mg/ml</span><span>.</span><span> </span

Effect of surfactant and electron treatment on the electrical and thermal conductivity as well as thermal and mechanical properties of ethylene vinyl acetate/expanded graphite composites

“…EVA-460 contains 18% by weight of vinyl acetate (VA) with a BHT antioxidant thermal stabilizer. It has a melt flow index (1908C/2.16 kg) of 2.5 g/10 min (ASTM D1238-ISO 1133), a melting temperature of 888C, a Vicat softening point of 648C, and a density of 0.941 g cm 23 . The sodium lauryl sulphate known as sodium dodecyl sulphate (SDS) was supplied by Sigma-Aldrich and was used without further treatment.…”

Synthesis of carbon nanotubes by arc-discharge and chemical vapor deposition method with analysis of its morphology, dispersion and functionalization characteristics

“…It was observed that the peak in the absorbance spectra increases at the beginning of sonication process. It is due to the fact that, increasing sonication time weakens the interaction force between individual nanotubes and results in more dispersion of nanotubes [30]. The SDS molecules adsorbed on the outer layer of MWCNT's prevent reaggregation.…”

Electro-conductive porous scaffold with single-walled carbon nanotubes in wormlike micellar networks

“…At high concentration of SWCNTs (above $4 wt%), the SWCNTs can aggregate or form bundles [13], making the encapsulation of SWCNTs in the FISP scaffold difficult and can clog the microchannel device. The concentration of SDS (1 wt%) used in this work has been previously reported as one of the optimal concentrations to disperse SWCNTs [13,29,34]. Hence, after many trials and errors, we used CTAB (0.9 wt%), SDS (1 wt%), and SWCNTs (1 wt%) as an optimal concentration combination to avoid crystallizations, bundling, or phase separation in the precursor solution (CTAB-NaSal-SDS-SWCNTs) for further electro-conductivity studies.…”

“…We dispersed 1 wt% of SDS and 1 wt% of SWCNTs in DI-water and sonicated the mixture for 5 h. Note that the critical micellar concentration (CMC) of SDS in water is $0.2 wt%. The dispersed solution was then incubated at room temperature for We can estimate the final concentration of SWCNTs in the dispersion based on ultraviolet spectroscopy data of the supernatant SDS-SWCNTs solution [29]. Shi et al [29] approximated the concentration of SWCNTs in an aqueous solution with SDS based on ultraviolet spectroscopy data of the supernatant SDS-SWCNTs solution, concluding that the supernatant solution contained $90% of the initial loading of SWCNTs in the solution.…”

“…The dispersed solution was then incubated at room temperature for We can estimate the final concentration of SWCNTs in the dispersion based on ultraviolet spectroscopy data of the supernatant SDS-SWCNTs solution [29]. Shi et al [29] approximated the concentration of SWCNTs in an aqueous solution with SDS based on ultraviolet spectroscopy data of the supernatant SDS-SWCNTs solution, concluding that the supernatant solution contained $90% of the initial loading of SWCNTs in the solution. Based on the UV-vis data of our precursor solution, we extrapolated the master curve data from Shi et al, showing $91 ± 0.3% of SWCNTs present in our initially prepared supernatant SDS-SWCNTs solution.…”