Rikhtehgaran Samaneh, Lohrasebi Amir
Department of Physics, Florida Atlantic University, Boca Raton, FL 33431, USA.
Department of Physics, University of Isfahan, Isfahan, 8174673441, Iran.
J Nanosci Nanotechnol. 2018 Aug 1;18(8):5799-5803. doi: 10.1166/jnn.2018.15467.
Porous graphene sheets can be considered as an ultrathin membrane in reverse osmosis water desalination processes. In this paper, employing the molecular dynamics simulation method, the performance of multilayer porous graphene membranes with different pore sizes, layer separation, and layer number were investigated. We found that salt rejection and water flux through the membrane significantly depend on the graphene pore size and number of graphene layers, and controlling these parameters could improve the filtration process. It was shown that our 2-layer designed graphene membranes with the pore radius of 3.3 Å and layer separation of 20 Å, can reject more than 86% of ions. Also, no filtration process had occurred for graphene layer separation less than 5 Å. The results of this study that are described by ion hydration radius and water velocity distributions can be used to improve the knowledge of water desalination at the molecular level, which leads to design more efficient multilayer graphene membranes for water purification.
多孔石墨烯片可被视为反渗透海水淡化过程中的一种超薄膜。本文采用分子动力学模拟方法，研究了不同孔径、层间距和层数的多层多孔石墨烯膜的性能。我们发现，盐分截留率和水通量显著取决于石墨烯孔径和石墨烯层数，控制这些参数可以改善过滤过程。结果表明，我们设计的孔径为3.3 Å、层间距为20 Å的双层石墨烯膜能够截留超过86%的离子。此外，当石墨烯层间距小于5 Å时，未发生过滤过程。这项研究的结果通过离子水合半径和水速度分布来描述，可用于增进分子水平上的海水淡化知识，从而设计出更高效的用于水净化的多层石墨烯膜。
