Mechanisms of carbon nanotube aggregation and the reversion of carbon nanotube aggregates in aqueous medium.

ABSTRACT: Single-walled carbon nanotubes (SWCNTs) dispersed in aqueous medium have many potential applications in chemistry, biology, and medicine. Reversible aggregation of SWCNTs dispersed in water has been frequently reported, but the mechanisms behind are not well understood. Here we show that SWCNTs dispersed into aqueous medium assisted by various charged molecules can be reversibly aggregated by a variety of electrolytes with two distinct mechanisms. Direct binding of counterions to SWCNTs leads to aggregation when the surface charge is neutralized from 74 to 86%. This aggregation is driven by electrostatic instead of van der Waals interactions, thus showing similarity to that of DNA condensation induced by multivalent cations. Sequestration of counterions by chelating reagents leads to the r

SUBMITTER: Koh B 

PROVIDER: S-EPMC4165447 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature