The influence of natural organic matter on the toxicity of multiwalled carbon nanotubes.

Engineered carbon nanostructures, such as multiwalled carbon nanotubes (MWNTs), are inherently hydrophobic and are not readily stable in aqueous media. However, the aqueous stability and bioavailability of these nanotubes may be influenced by the water quality parameters such as ionic strength, pH, and natural organic matter (NOM). Natural organic matter adsorbs onto the surface of MWNTs, effectively covering the hydrophobic surface and resulting in increased aqueous stability.