Aqueous stability of oxidized carbon nanotubes and the precipitation by salts

Drug loading, dispersion stability, and therapeutic efficacy in targeted drug delivery with carbon nanotubes

“…This was not surprising, as it is well-known that oxidised carbon nanotubes give rise to electrostatic interactions with salts, such as the two anticancer drugs investigated here, which can impair the dispersion stability due to charge neutralisation [20]. Precipitation did not influence the efficacy of drug binding; but it is of course essential that any clinical formulation remains stable in the circulation, so dispersion stability is critical.…”

Aqueous stability and mobility of C60 complexed by sodium dodecyl benzene sulfonate surfactant

“…The suspended mass and ζ-potential potential varied by < 5% over a 17-day period (Bouchard et al, 2012). Oxidized MWCNTs were reported to have a concentration decrease of only 15% even after 30-day aging (Peng et al, 2009). It is shown in Fig.…”

“…Recently, the electrokinetic characteristics of several kinds of modified nano-materials have been of concern and were documented. Previous investigation showed that oxidized multi-walled carbon nanotubes (MWCNTs) had negative ζ-potentials in the range of −31.0 to −49.5 mV in the pH range 2.6-6.5, and a ζ-potential value of −49.5 mV was measured under near-neutral pH conditions (Peng et al, 2009). The ζ-potential value of oxidized single-walled carbon nanotubes (SWCNTs) reached −45 mV (Li et al, 2008).…”

“…Surface modification of colloidal particles can significantly enhance their stability. After the modification process of oxidation, CCC values for SWCNTs and MWCNTs reached 160 mmol/L (Li and Huang, 2010) and 185 mmol/L (Peng et al, 2009), respectively. That of surfactant-complexed SWCNTs varied in the range of 121-871 mmol/L, depending on the surfactant concentration adopted (Bouchard et al, 2012).…”

Multi-walled carbon nanotube dispersion by the adsorbed humic acids with different chemical structures

“…The coating of MWCNTs by HA (or surfactants) can decrease MWCNT hydrophobicity (Hyung et al, 2007;Chappell et al, 2009) (Table 1) while increasing MWCNT electrostatic repulsion (Jiang et al, 2003;Chen et al, 2004;Zhou et al, 2012) (as suggested by the negative charge in Fig. S7) and steric hindrance (Jiang et al, 2003;Peng et al, 2009;Zhou et al, 2012), leading to enhanced MWCNT suspension.…”