中国物理B ›› 2015, Vol. 24 ›› Issue (10): 108201-108201.doi: 10.1088/1674-1056/24/10/108201

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Ion and water transport in charge-modified graphene nanopores

裘英华, 李堃, 陈伟宇, 司伟, 谭启檐, 陈云飞   

  1. School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, China
  • 收稿日期:2015-01-22 修回日期:2015-04-06 出版日期:2015-10-05 发布日期:2015-10-05
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant Nos. 2011CB707601 and 2011CB707605), the National Natural Science Foundation of China (Grant No. 50925519), the Fundamental Research Funds for the Central Universities, Funding of Jiangsu Provincial Innovation Program for Graduate Education, China (Grant No. CXZZ13_0087), and the Scientific Research Foundation of Graduate School of Southeast University (Grant No. YBJJ 1322).

Ion and water transport in charge-modified graphene nanopores

Qiu Ying-Hua (裘英华), Li Kun (李堃), Chen Wei-Yu (陈伟宇), Si Wei (司伟), Tan Qi-Yan (谭启檐), Chen Yun-Fei (陈云飞)   

  1. School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, China
  • Received:2015-01-22 Revised:2015-04-06 Online:2015-10-05 Published:2015-10-05
  • Contact: Chen Yun-Fei E-mail:yunfeichen@seu.edu.cn
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant Nos. 2011CB707601 and 2011CB707605), the National Natural Science Foundation of China (Grant No. 50925519), the Fundamental Research Funds for the Central Universities, Funding of Jiangsu Provincial Innovation Program for Graduate Education, China (Grant No. CXZZ13_0087), and the Scientific Research Foundation of Graduate School of Southeast University (Grant No. YBJJ 1322).

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摘要： Porous graphene has a high mechanical strength and an atomic-layer thickness that makes it a promising material for material separation and biomolecule sensing. Electrostatic interactions between charges in aqueous solutions are a type of strong long-range interaction that may greatly influence fluid transport through nanopores. In this study, molecular dynamic simulations were conducted to investigate ion and water transport through 1.05-nm diameter monolayer graphene nanopores, with their edges charge-modified. Our results indicated that these nanopores are selective to counterions when they are charged. As the charge amount increases, the total ionic currents show an increase-decrease profile while the co-ion currents monotonically decrease. The co-ion rejection can reach 76.5% and 90.2% when the nanopores are negatively and positively charged, respectively. The Cl- ion current increases and reaches a plateau, and the Na+ current decreases as the charge amount increases in systems in which Na+ ions act as counterions. In addition, charge modification can enhance water transport through nanopores. This is mainly due to the ion selectivity of the nanopores. Notably, positive charges on the pore edges facilitate water transport much more strongly than negative charges.

关键词: monolayer porous graphene, charge-modified nanopore, ion selectivity, ionic current, water transport

Abstract: Porous graphene has a high mechanical strength and an atomic-layer thickness that makes it a promising material for material separation and biomolecule sensing. Electrostatic interactions between charges in aqueous solutions are a type of strong long-range interaction that may greatly influence fluid transport through nanopores. In this study, molecular dynamic simulations were conducted to investigate ion and water transport through 1.05-nm diameter monolayer graphene nanopores, with their edges charge-modified. Our results indicated that these nanopores are selective to counterions when they are charged. As the charge amount increases, the total ionic currents show an increase-decrease profile while the co-ion currents monotonically decrease. The co-ion rejection can reach 76.5% and 90.2% when the nanopores are negatively and positively charged, respectively. The Cl- ion current increases and reaches a plateau, and the Na+ current decreases as the charge amount increases in systems in which Na+ ions act as counterions. In addition, charge modification can enhance water transport through nanopores. This is mainly due to the ion selectivity of the nanopores. Notably, positive charges on the pore edges facilitate water transport much more strongly than negative charges.

Key words: monolayer porous graphene, charge-modified nanopore, ion selectivity, ionic current, water transport

中图分类号:  (Computational modeling; simulation)

  • 82.20.Wt
89.40.Cc (Water transportation) 92.05.Hj (Physical and chemical properties of seawater) 68.65.Pq (Graphene films)