Structure and properties of aqueous dispersions of sodium dodecyl sulfate with carbon nanotubes

Optimization of highly concentrated dispersions of multi-walled carbon nanotubes with emphasis on surfactant content and carbon nanotubes quality

“…All resulting aqueous solutions were sonicated for 1 h with an ultrasonic homogenizer (Bandelin Sonopuls® UW2200) with active intervals of 0.1 s, passive intervals of 0.9 s, amplitude fixed at 50% and a power equals to 200 W. Subsequently, the solutions were centrifuged for 5 min at 2680 g0 in order to bring bundles as well as residual catalyst particles to the bottom of the centrifuge tubes [17], [19], [25], [27], [36]. The supernatants were selected and further characterized.…”

Modified method of conductometric data analysis to calculate the conductivity of surfactant ions

“…The obtained values in the presence of data on the aggregation number of ions in the micelle N allow to calculate by the Evans formula [11,19]  = [-+ + (+ 2 + 4·-·b·N 2/3 ) 1/2 ] (2·-·N 2/3 ) -1 (7) and by other formulae given in part 1 of this article, in particular, The use of the limiting law revealed a very good agreement of the results related to SDS ions. However the results for the degree of micelle ionization  (9), in our opinion, turned out to be slightly underestimated, and for conductivities of micelles, on the contrary, slightly overestimated.…”

“…Numerical calculations are performed using the example of one of the most studied anionic surfactants -sodium dodecyl sulfate (SDS). The choice of this surfactant was dictated by our experience in studying SDS solutions [5,6] and phenomena occurring on the surfaces of carbon nanotubes dispersed in these solutions [7][8][9].…”

Morphology of Ionic Micelles as Studied by Numerical Solution of the Poisson Equation

“…Surfactants in molecular form and organized assemblies are of great fundamental, technological, and commercial interest stimulating further insight into their physical–chemical properties and enormous prospective applications, including pharmacology, agrochemistry, household chemistry, cosmetics, biotechnology, and nanomedicine. − In addition, surfactants are of considerable importance in the oil industry, for example for enhanced oil recovery, oil transportation and processing. − Many novel technologies are difficult without nanoparticle stabilization in water or oil. In particular, surfactants are needed for obtaining carbon nanotube dispersions. − The development of surfactant-based technologies and applications demands reliable information about the physicochemical characteristics of surfactants in various structural states.…”