Intrinsic ion transport of highly charged sub-3-nm boron nitride nanotubes
Intrinsic ion transport of highly charged sub-3-nm boron nitride nanotubes
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DOI：
10.1016/j.mattod.2022.09.006
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发表时间：
2022-10
期刊：
影响因子：
24.2
通讯作者：
A. Pendse;Semih Cetindag;Kun Wang;Donglin Li;Richard J. Castellano;Da-Chi Yang;Tongshuai Wang
中科院分区：
文献类型：
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作者：
A. Pendse;Semih Cetindag;Kun Wang;Donglin Li;Richard J. Castellano;Da-Chi Yang;Tongshuai Wang
由于缺乏实验数据，关于水和离子在高电荷一维（1D）纳米通道中的传输机制的争论仍在继续。在这里，我们提出了一个纳米流体平台组成的2.7 nm直径的氮化硼纳米管（BNNTs）作为一个模型系统，并报告在这些子3 nm的BNNTs的实验离子传输。我们阐明，强静电之间的相互作用，高度带电的管壁和离子，源于高表面电荷密度（378 mC/m2）的BNNT，在定义BNNT孔的离子传输机制中发挥重要作用。离子输运的实验分析支持的数值的Donnan空间孔模型与介电排斥（DSPM-DE）和Derjaguin-Landau-Verwey-Overbeek（DLVO）模型阐明的离子电荷密度和表面电荷密度的BNNT壁的静电相互作用，空间和介电效应的关系。我们还表明，BNNT表现出更高的NaCl分离（90%）比商业反渗透（80%）和纳滤（60%）膜在相同的实验条件下，尽管有一个更大的孔径。我们的研究结果建立了设计标准，开发高效的离子选择性膜的各种实际应用。
Debate regarding the transport mechanisms of water and ions in highly charged one-dimensional (1D) nanochannel continues because of a lack of available experimental data. Here, we present a nanofluidic platform consisting of ≈2.7-nm-diameter boron nitride nanotubes (BNNTs) as a model system, and report the experimental ion transport in these sub-3-nm BNNTs. We elucidate that strong electrostatic interactions between the highly charged tube walls and ions, stemming from the high surface-charge density (378 mC/m2) of BNNTs, play important roles in defining the ion transport mechanism in BNNT pores. Experimental analysis of ion transports supported by numerical the Donnan steric pore model with dielectric exclusion (DSPM-DE) and Derjaguin–Landau–Verwey–Overbeek (DLVO) model elucidate the relationship of the ionic charge density and surface-charge density of the BNNT wall to electrostatic interaction, steric, and dielectric effects. We also demonstrate that BNNTs exhibit higher NaCl separation (≈90%) than commercial reverse-osmosis (≈80%) and nanofiltration (≈60%) membranes under the same experimental conditions, despite having a larger pore size. Our results establish design criteria for developing highly efficient ion-selective membranes for various practical applications.