Sun Zhenyu, Nicolosi Valeria, Bergin Shane D, Coleman Jonathan N
Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, University of Dublin, Dublin 2, Republic of Ireland. School of Physics, Trinity College Dublin, University of Dublin, Dublin 2, Republic of Ireland.
Nanotechnology. 2008 Dec 3;19(48):485702. doi: 10.1088/0957-4484/19/48/485702. Epub 2008 Nov 12.
A novel amine solvent, 3-aminopropyltriethoxysilane, has been used to disperse single-walled carbon nanotubes. Well-dispersed nanotubes in the form of small bundles coexist in the liquid phase with large nanotube aggregates. A mild centrifugation step can be used to remove the aggregates. By measurement of the absorbance before and after centrifugation as a function of concentration, the fraction of the dispersed nanotube phase can be estimated. As measured by atomic force microscopy, the mean bundle diameter tends to decrease with decreasing concentration and levels off below a concentration of ∼0.012 mg ml(-1). Individual nanotubes are always observed, whose population increases with decreasing concentration before saturating at a concentration of ∼0.012 mg ml(-1). The absolute number of individual nanotubes per volume of dispersion initially increases with decreasing concentration, and then reaches a peak at a concentration of ∼0.024 mg ml(-1). Further experimental results showed that nanotubes can also be effectively dispersed in a series of aminoalkoxylsilane derivatives. In the light of these findings, possible solvent-nanotube interaction mechanisms are discussed.
一种新型胺类溶剂3-氨丙基三乙氧基硅烷已被用于分散单壁碳纳米管。小束状的分散良好的纳米管与大的纳米管聚集体共存于液相中。可以通过温和的离心步骤去除聚集体。通过测量离心前后吸光度随浓度的变化，可以估算出分散纳米管相的比例。通过原子力显微镜测量，平均束直径倾向于随着浓度降低而减小，并在浓度低于约0.012 mg ml⁻¹时趋于稳定。总是能观察到单根纳米管，其数量随着浓度降低而增加，在浓度约为0.012 mg ml⁻¹时达到饱和。每单位体积分散体中单个纳米管的绝对数量最初随着浓度降低而增加，然后在浓度约为0.024 mg ml⁻¹时达到峰值。进一步的实验结果表明，纳米管也能有效地分散在一系列氨基烷氧基硅烷衍生物中。根据这些发现，讨论了可能的溶剂-纳米管相互作用机制。
