Nicolosi Valeria, Cathcart Helen, Dalton Alan R, Aherne Damian, Dieckmann Gregg R, Coleman Jonathan N
School of Physics, Trinity College Dublin, Dublin 2, Ireland.
Biomacromolecules. 2008 Feb;9(2):598-602. doi: 10.1021/bm701181j. Epub 2008 Jan 26.
We have observed concentration dependent exfoliation of single-walled carbon nanotubes dispersed in solutions of the synthetic peptide nano-1. As the nanotube concentration is reduced, the bundle diameters tend to decrease before saturating at <2.0 nm for concentrations below 6 x 10(-3) mg/mL. The fraction of individual nanotubes increases with decreasing concentration, saturating at approximately 95% at low concentration. This concentration dependent exfoliation happens even if the dispersions are not sonicated on dilution, albeit over a longer time scale. The populations both of individual nanotubes and of bundles are much higher than expected at high concentrations, indicating the presence of repulsive internanotube interactions stabilizing the dispersions.
我们观察到，分散在合成肽nano-1溶液中的单壁碳纳米管会发生浓度依赖性剥落。随着纳米管浓度降低，束直径往往会先减小，在浓度低于6×10⁻³mg/mL时，束直径在<2.0 nm时达到饱和。单个纳米管的比例随浓度降低而增加，在低浓度时约95%达到饱和。即使稀释时不对分散体进行超声处理，这种浓度依赖性剥落也会发生，尽管时间尺度更长。在高浓度下，单个纳米管和管束的数量都比预期的要高得多，这表明存在排斥性的纳米管间相互作用来稳定分散体。
