Department of Electrical & Computer Engineering, Hellenic Mediterranean University, Heraklion 71410, Crete, Greece.
Department of Electrical & Computer Engineering, Hellenic Mediterranean University, Heraklion 71410, Crete, Greece.
J Colloid Interface Sci. 2020 Nov 15;580:332-344. doi: 10.1016/j.jcis.2020.07.040. Epub 2020 Jul 11.
The formation of highly concentrated and stable graphene derivatives dispersions remains a challenge towards their exploitation in various applications, including flexible optoelectronics, photovoltaics, 3D-printing, and biomedicine. Here, we demonstrate our extensive investigation on the dispersibility of graphene oxide (GO) and reduced graphene oxide (RGO) in 25 different solvents, without the use of any surfactant or stabilizer. Although there is a significant amount of work covering the general field, this is the first report on the dispersibility of: a) RGO prepared by a HI/AcOH assisted reduction process, the method which yields RGO of higher graphitization degree than the other well-known reductants met in the literature, b) both GO and RGO, explored in such a great range of solvents, with some of them not previously reported. In addition, through calculation of their Hansen Solubility Parameters (HSP), we confirmed their dispersibility behavior in each solvent, while we indirectly validated the most advanced graphitization degree of the studied RGO compared to other reported RGOs, since its HSPs exhibit the highest similarity with the respective ones of pure graphene. Finally, high concentrations of up to 189 μg mL for GO and ~ 87.5 μg mL for RGO were achieved, in deionized water and o-Dichlorobenzene respectively, followed by flakes size distribution and polydispersity indices estimation, through dynamic light scattering as a quality control of the effect of a solvent's nature on the dispersion behavior of these graphene-based materials.
高度浓缩和稳定的石墨烯衍生物分散体的形成仍然是一个挑战，这阻碍了它们在各种应用中的开发，包括柔性光电、光伏、3D 打印和生物医学。在这里，我们展示了我们对氧化石墨烯（GO）和还原氧化石墨烯（RGO）在 25 种不同溶剂中的分散性的广泛研究，而无需使用任何表面活性剂或稳定剂。尽管已经有大量的工作涵盖了一般领域，但这是第一篇关于以下方面的分散性的报告：a）通过 HI/AcOH 辅助还原过程制备的 RGO，该方法得到的 RGO 的石墨化程度高于文献中报道的其他常见还原剂，b）GO 和 RGO，在如此广泛的溶剂范围内进行探索，其中一些溶剂以前没有报道过。此外，通过计算它们的 Hansen 溶解度参数（HSP），我们证实了它们在每种溶剂中的分散行为，同时我们间接地验证了所研究的 RGO 比其他报道的 RGO 具有更高的先进石墨化程度，因为它的 HSP 与纯石墨烯的相应 HSP 具有最高的相似性。最后，在去离子水和邻二氯苯中，GO 分别达到了高达 189μg mL-1和~87.5μg mL-1的高浓度，然后通过动态光散射进行片状尺寸分布和多分散指数估计，作为对溶剂性质对这些基于石墨烯材料的分散行为影响的质量控制。
