MackGraphe - Graphene and Nanomaterials Research Center, Mackenzie Presbyterian University, São Paulo, 01302-907, Brazil.
Anal Methods. 2020 Jul 28;12(28):3575-3581. doi: 10.1039/d0ay00600a. Epub 2020 Jul 2.
The purification process of graphene oxide (GO) is a key stage in the production of this two-dimensional material by the Hummers method. This step demands a large amount of water, energy and time. The inefficient removal of the contaminants present in GO may affect its properties and make it unfeasible for some applications, such as in the field of biology. Here, we develop a simple and efficient method for the purification of an aqueous GO dispersion based on a fluidic diffusion cell system with a porous nitrocellulose membrane. The effectiveness of the fluidic diffusion cell system was compared with that of traditional purification methods, such as dialysis and centrifugation. The proposed strategy achieves the best performance in the removal of the major contaminants (K, Na, Cl, SO, Mn and MnO), demanding ∼95% less water than dialysis and in a shorter time (∼23 h). The system operates under flow conditions, with minimum handling by the operator and is able to select the GO flakes with bigger lateral dimensions. This work represents a simple and fast alternative for purification of GO dispersions that can be easily scaled-up.
氧化石墨烯（GO）的纯化过程是通过 Hummers 法生产这种二维材料的关键阶段。该步骤需要大量的水、能源和时间。GO 中存在的污染物去除不彻底，可能会影响其性能，使其无法应用于某些领域，如生物学领域。在这里，我们开发了一种基于具有多孔硝酸纤维素膜的流体扩散池系统的简单、高效的纯化水相 GO 分散体的方法。比较了流体扩散池系统与传统纯化方法（如透析和离心）的效果。该策略在去除主要污染物（K、Na、Cl、SO、Mn 和 MnO）方面表现出最佳性能，所需水比透析少约 95%，时间缩短约 23 小时。该系统在流动条件下运行，操作人员的操作最少，并且能够选择具有较大横向尺寸的 GO 薄片。这项工作为 GO 分散体的纯化提供了一种简单、快速的替代方法，易于放大。
