Colloidal and rheological characterization of SWCNT in biological media

Arisbel Cerpa, Isabel Lado, Oriella Quiroga, Rodrigo Moreno, Rosario García, Sebastián Cerdán, Nehal I. Abu-Lail
2019 International Journal of Smart and Nano Materials  
We report on the colloidal and rheological characterization of suspensions of commercial single-walled carbon nanotubes (SWCNT) and oxidized single walled carbon nanotubes (SWCNT-oxi24h), in water and fetal bovine serum (FBS). The effects of two surfactants, dodecyl-benzene sodium sulfonate (SBDS) and sodium dodecyl sulfate (SDS) at different concentrations (0.5-2.0%) on the zeta potential and the rheology of the suspensions is also investigated. SWCNT suspensions were characterized by
more » ... terized by Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). The colloidal stability was determined by measurements of zeta potential in the physiological pH range 6.0 < pH <8.0. Rheological measurements were implemented at concentrations of 1 and 1.5 mg/ml, and temperatures of 25°C, 30°C, and 37°C. The results obtained show that SWCNT suspensions in FBS, with and without addition of surfactants, depict a high tendency to aggregate with the bovine serum albumin (BSA), a process we could further characterize using Molecular Dynamics (MD) simulation. SWCNT suspensions in aqueous media show a negative zeta potential between −60 and −80 mV, whereas in FBS the stability is lower, with values of-20 mV. We observed no significant changes in the zeta potential with the different surfactants. The viscosity values obtained are smaller in water than in FBS, demonstrating the higher stability in water.
doi:10.1080/19475411.2019.1694555 fatcat:mihzjqxwq5hkhgobjuyinektim