摘要
具有高且稳定离子输运特性的二维层状薄膜在纳米流体器件中具有广泛的应用,但是它们的构建仍然是一个相当大的挑战.本文设计并开发了一种超稳定的芳纶纳米纤维/石墨复合薄膜,其内部包含大量的一维和二维纳米受限空间,可以实现超快的离子传输.这种薄膜不仅具有良好的柔性和可拓展性,同时还表现出优异的力学性能,即使在水中浸泡90天仍具有高的拉伸强度(~115.3 MPa).并且该薄膜在低的盐浓度下具有表面电荷控制的离子输运特性,在10^(-4)mol/LKCl浓度下,其离子电导率相对于原始KCl溶液提高了16倍.最重要的是,即使在酸、碱、乙醇等极端环境中浸泡30天以上,薄膜的结构和离子电导率仍保持稳定.分子动力学模拟进一步揭示了薄膜的超稳定性是源于纳米纤维内部强大的链间作用以及纳米纤维与石墨纳米片之间强大的界面相互作用.这种柔性、可扩展、超稳定的芳纶纳米纤维/石墨复合薄膜可能为先进的纳米流体器件在不同极端工作环境下的应用提供一种有效的策略.
Two-dimensional layered membranes with high and stable ion transport properties have various applications in nanofluidic devices;however,their construction remains a considerable challenge.Herein,we develop a superstable aramid nanofiber/graphite composite membrane with numerous one-dimensional and two-dimensional nano-confined interspaces for ultrafast ion transport.The fabricated flexible and scalable membrane exhibits high tensile strength(~115.3 MPa)even after immersion in water for 90 days.Further,the aramid nanofiber/graphite conductor features the surface-charge-governed ion transport behavior.The ionic conductivity of the membrane at a low potassium chloride concentration of 10^(-4) mol/L can be enhanced by 16 times that of the bulk counterpart.More importantly,its structure and ionic conductivity remain unchanged even after immersion in different harsh solutions(e.g.,acid,base,and ethanol)for over 30 days.Molecular dynamics simulations reveal that the superstability of the membrane is attributable to the robust interchain interactions within the aramid nanofibers and the strong interfacial interactions between the aramid nanofibers and graphite nanosheets.This study highlights the superior structural stability of the proposed flexible and scalable aramid nanofiber/-graphite composite membrane,which could be employed in advanced nanofluidic devices for application under extreme working environments.
作者
司联蒙
吴宜涵
肖鸿
邢文思
宋睿
李一举
王莎
梁旭
郁汶山
宋建伟
申胜平
Lianmeng Si;Yihan Wu;Hong Xiao;Wensi Xing;Rui Song;Yiju Li;Sha Wang;Xu Liang;Wenshan Yu;Jianwei Song;Shengping Shen(State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen 518055,China;Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources,Nanjing Forestry University,Nanjing 210037,China)
基金
supported by the National Natural Science Foundation of China(11902243 and 51903124)
the Young Elite Scientist Sponsorship Program by CAST(2019QNRC001)
the“1000-Plan Program”of Shaanxi Province
the“Young Talent Support Plan”of Xi’an Jiaotong University
Initiative Funds of Scientific Research for Metasequoia Talent(163105049)。
