Dispersing carbon nanotubes is an easy and low-cost way to manipulate these solids and allows the preparation of more complex materials or devices, so it is fundamental for further uses that these dispersions have controlled properties and high colloidal stability. In this work we report the spontaneous electrical charge build-up in pristine multi-walled carbon nanotubes dispersed in common organic solvents such as chloroform and tetrahydrofuran and the achievement of dispersions stable for long periods without adding passivant agents or functional groups on nanotubes surface. Results from electrokinetics, homo- and heterocoagulation provided macroscopic evidences that carbon nanotubes acquire electric charges after dispersion in some organic liquids and we confirmed this process by measuring in situ Raman spectra of the nanotubes dispersions with higher surface electric potentials. We also show that the signal of electric potential of the dispersions can be predicted by the acid-base behaviour of the dispersing medium, corroborating previously reports for other dispersions of carbon nanomaterials.

分散碳纳米管是一种操作这些固体的简便且低成本的方法，可以制备更复杂的材料或装置，因此，进一步分散使用这些分散体具有可控制的性能和高胶体稳定性是至关重要的。在这项工作中，我们报告了分散在普通有机溶剂（如氯仿和四氢呋喃）中的原始多壁碳纳米管中的自发电荷积累，以及实现了长时间稳定而无需在纳米管表面添加钝化剂或官能团的分散体。电动学，均相和杂凝的结果提供了宏观的证据，即碳纳米管分散在某些有机液体中后会获得电荷，我们通过现场测量证实了这一过程。具有较高表面电势的纳米管分散体的拉曼光谱。我们还表明，分散体的电势信号可以通过分散介质的酸碱行为来预测，从而证实了先前对于碳纳米材料其他分散体的报道。