Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.
School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, Pathum Thani, 12120, Thailand.
Nanoscale. 2023 May 18;15(19):8716-8729. doi: 10.1039/d2nr06969e.
Graphene oxide (GO) membranes have gained great attention for water purification due to the formation of stacked nanosheets giving nanocapillary channels. Unlike graphene, the interlayer spacing of GO membranes gets readily expanded in aqueous solution due to their high oxygen content, resulting in poor ion rejection. Herein, we prepared ultralow oxygen-containing graphene (∼1 at%) facile liquid-phase exfoliation which was formed as membrane laminates. The graphene membranes exhibited ultrahigh stability with no observed swelling or deformation of the laminar structure when kept in water, aqueous salt solutions, and various pH solutions for over one week. The membranes with a high degree of tortuous nanocapillary channels can efficiently reject the ions found in seawater as well as various charged dye molecules. This indicates that the graphene membranes exhibited ionic and molecular sieving properties due to the effect of size exclusion obtained from the narrow nanocapillary channel and electrostatic repulsion from negatively charged graphene nanosheets. Moreover, we also demonstrated machine learning to gain insights into the membrane performance, which allowed us to obtain membrane optimization as a model for water purification technology.
氧化石墨烯（GO）膜因其纳米片堆叠形成纳米毛细管通道而在水净化方面受到广泛关注。与石墨烯不同，由于其高氧含量，GO 膜的层间距在水溶液中很容易扩展，导致离子截留率差。在此，我们制备了超低含氧（约 1 原子%）的易于液相剥离的氧化石墨烯，其形成了膜层压板。当石墨烯膜在水中、盐水溶液和各种 pH 溶液中保持超过一周时，表现出超高的稳定性，没有观察到层状结构的溶胀或变形。具有高度曲折纳米毛细管通道的膜可以有效地排斥海水中的离子以及各种带电染料分子。这表明石墨烯膜由于来自狭窄纳米毛细管通道的尺寸排除效应和来自带负电荷的石墨烯纳米片的静电排斥，表现出离子和分子筛分特性。此外，我们还通过机器学习深入了解膜性能，从而获得膜优化作为水净化技术的模型。
