1
|
Noh Y, Aluru NR. Scaling of ionic conductance in a fluctuating single-layer nanoporous membrane. Sci Rep 2023; 13:19813. [PMID: 37957224 PMCID: PMC10643653 DOI: 10.1038/s41598-023-46962-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 11/07/2023] [Indexed: 11/15/2023] Open
Abstract
Single-layer membranes have emerged as promising candidates for applications requiring high transport rates due to their low resistance to molecular transport. Owing to their atomically thin structure, these membranes experience significant microscopic fluctuations, emphasizing the need to explore their impact on ion transport processes. In this study, we investigate the effects of membrane fluctuations on the elementary scaling behavior of ion conductance [Formula: see text] as a function of ion concentration [Formula: see text], represented as [Formula: see text], using molecular dynamics simulations. Our findings reveal that membrane fluctuations not only alter the conductance coefficient [Formula: see text] but also the power-law exponent [Formula: see text]. We identify two distinct frequency regimes of membrane fluctuations, GHz-scale and THz-scale fluctuations, and examine their roles in conductance scaling. Furthermore, we demonstrate that the alteration of conductance scaling arises from the non-linearity between ion conductance and membrane shape. This work provides a fundamental understanding of ion transport in fluctuating membranes.
Collapse
Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - N R Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, 78712, USA.
| |
Collapse
|
2
|
Nazemzadeh N, Miranda CR, Liang Y, Andersson MP. First-Principles Prediction of Amorphous Silica Nanoparticle Surface Charge: Effect of Size, pH, and Ionic Strength. J Phys Chem B 2023; 127:9608-9619. [PMID: 37906160 DOI: 10.1021/acs.jpcb.3c04405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
The quantification of surface charge properties of silica nanoparticles is essential for several applications. To determine these properties, many experimental and theoretical methods have been introduced, which are time-consuming and/or challenging to use. In this study, a first-principles approach is developed to determine the surface charge properties of amorphous silica nanoparticles against the nanoparticle size, pH, and ionic strength without relying on experimental data. An amorphous silica nanoparticle of 1.34 nm diameter is simulated by using integrated molecular dynamics and Monte Carlo methods. A detailed analysis of the nanoparticle structure is provided by analyzing the types of silanol groups on the surface. Moreover, a model is developed to estimate the probability distribution of the surface silanol groups based on the nearest neighbor distances and the diameter of the nanoparticle to determine the number of surface silanols on larger nanoparticles. Thereafter, a computational chemistry approach is used to calculate the acid dissociation constants of the corresponding deprotonation reactions. The calculated constants and the point of zero charge value are in excellent agreement with experiments. The surface charge properties of the nanoparticle with various diameters are then estimated by using a mean-field model at different pH and ionic strength values. The results of the developed model are compared to the Poisson-Boltzmann equation as a reference model. The developed model predictions agree well with the reference model for low and mid-electrolyte concentrations (1 and 10 mM) and small nanoparticles (smaller than 100 nm). However, the developed model seems to qualitatively predict the surface charge properties more accurately than the Poisson-Boltzmann model for high electrolyte concentrations.
Collapse
Affiliation(s)
- Nima Nazemzadeh
- Department of Chemical and Biochemical Engineering, Søltofts Plads, Building 228A, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Caetano R Miranda
- Institute of Physics, University of São Paulo, P.O. Box 66318, São Paulo 05508-090, SP, Brazil
| | - Yunfeng Liang
- Department of Systems Innovation, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Martin P Andersson
- Center for Integrative Petroleum Research, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
| |
Collapse
|
3
|
Noh Y, Aluru NR. Ion transport in two-dimensional flexible nanoporous membranes. NANOSCALE 2023. [PMID: 37337690 DOI: 10.1039/d3nr00875d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Ion transport is a fundamental mechanism in living systems that plays a role in cell proliferation, energy conversion, and maintaining homeostasis. This has inspired various nanofluidic applications such as electricity harvesting, molecular sensors, and molecular separation. Two dimensional (2D) nanoporous membranes are particularly promising for these applications due to their ultralow transport barriers. We investigated ion conduction across flexible 2D membranes via extensive molecular dynamics simulations. We found that the microscopic fluctuations of these membranes can significantly increase ion conductance, for example, by 320% in Cu-HAB with 0.5 M KCl. Our analysis of ion dynamics near the flexible membranes revealed that ion hydration is destabilized when the membrane fluctuated within a specific frequency range leading to improved ion conduction. Our results show that the dynamic coupling between the fluctuating membrane and ions can play a crucial role in ion conduction across 2D nanoporous membranes.
Collapse
Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Narayana R Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering & Sciences, University of Texas at Austin, Austin 78712, USA.
| |
Collapse
|
4
|
Aluru NR, Aydin F, Bazant MZ, Blankschtein D, Brozena AH, de Souza JP, Elimelech M, Faucher S, Fourkas JT, Koman VB, Kuehne M, Kulik HJ, Li HK, Li Y, Li Z, Majumdar A, Martis J, Misra RP, Noy A, Pham TA, Qu H, Rayabharam A, Reed MA, Ritt CL, Schwegler E, Siwy Z, Strano MS, Wang Y, Yao YC, Zhan C, Zhang Z. Fluids and Electrolytes under Confinement in Single-Digit Nanopores. Chem Rev 2023; 123:2737-2831. [PMID: 36898130 PMCID: PMC10037271 DOI: 10.1021/acs.chemrev.2c00155] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Confined fluids and electrolyte solutions in nanopores exhibit rich and surprising physics and chemistry that impact the mass transport and energy efficiency in many important natural systems and industrial applications. Existing theories often fail to predict the exotic effects observed in the narrowest of such pores, called single-digit nanopores (SDNs), which have diameters or conduit widths of less than 10 nm, and have only recently become accessible for experimental measurements. What SDNs reveal has been surprising, including a rapidly increasing number of examples such as extraordinarily fast water transport, distorted fluid-phase boundaries, strong ion-correlation and quantum effects, and dielectric anomalies that are not observed in larger pores. Exploiting these effects presents myriad opportunities in both basic and applied research that stand to impact a host of new technologies at the water-energy nexus, from new membranes for precise separations and water purification to new gas permeable materials for water electrolyzers and energy-storage devices. SDNs also present unique opportunities to achieve ultrasensitive and selective chemical sensing at the single-ion and single-molecule limit. In this review article, we summarize the progress on nanofluidics of SDNs, with a focus on the confinement effects that arise in these extremely narrow nanopores. The recent development of precision model systems, transformative experimental tools, and multiscale theories that have played enabling roles in advancing this frontier are reviewed. We also identify new knowledge gaps in our understanding of nanofluidic transport and provide an outlook for the future challenges and opportunities at this rapidly advancing frontier.
Collapse
Affiliation(s)
- Narayana R Aluru
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, 78712TexasUnited States
| | - Fikret Aydin
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Martin Z Bazant
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Daniel Blankschtein
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Alexandra H Brozena
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
| | - J Pedro de Souza
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Menachem Elimelech
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut06520-8286, United States
| | - Samuel Faucher
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - John T Fourkas
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland20742, United States
- Maryland NanoCenter, University of Maryland, College Park, Maryland20742, United States
| | - Volodymyr B Koman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Matthias Kuehne
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Hao-Kun Li
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Yuhao Li
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Zhongwu Li
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Joel Martis
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Rahul Prasanna Misra
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Aleksandr Noy
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
- School of Natural Sciences, University of California Merced, Merced, California95344, United States
| | - Tuan Anh Pham
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Haoran Qu
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
| | - Archith Rayabharam
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, 78712TexasUnited States
| | - Mark A Reed
- Department of Electrical Engineering, Yale University, 15 Prospect Street, New Haven, Connecticut06520, United States
| | - Cody L Ritt
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut06520-8286, United States
| | - Eric Schwegler
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Zuzanna Siwy
- Department of Physics and Astronomy, Department of Chemistry, Department of Biomedical Engineering, University of California, Irvine, Irvine92697, United States
| | - Michael S Strano
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - YuHuang Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
- Maryland NanoCenter, University of Maryland, College Park, Maryland20742, United States
| | - Yun-Chiao Yao
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
- School of Natural Sciences, University of California Merced, Merced, California95344, United States
| | - Cheng Zhan
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Ze Zhang
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| |
Collapse
|
5
|
Zhuang J, Ma L, Qiu Y. Characterization of the surface charge property and porosity of track-etched polymer membranes. Electrophoresis 2022; 43:2428-2435. [PMID: 36193776 DOI: 10.1002/elps.202200198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/20/2022] [Accepted: 09/25/2022] [Indexed: 12/13/2022]
Abstract
As an important property of porous membranes, the surface charge property determines many ionic behaviors of nanopores, such as ionic conductance and selectivity. Based on the dependence of electric double layers on bulk concentrations, ionic conductance through nanopores at high and low concentrations is governed by the bulk conductance and surface charge density, respectively. Here, through the investigation of ionic conductance inside track-etched single polyethylene terephthalate (PET) nanopores under various concentrations, the surface charge density of PET membranes is extracted as ∼-0.021 C/m2 at pH 10 over measurements with 40 PET nanopores. Simulations show that surface roughness can cause underestimation in surface charge density due to the inhibited electroosmotic flow. Then, the averaged pore size and porosity of track-etched multipore PET membranes are characterized by the developed ionic conductance method. Through coupled theoretical predictions in ionic conductance under high and low concentrations, the averaged pore size and porosity of porous membranes can be obtained simultaneously. Our method provides a simple and precise way to characterize the pore size and porosity of multipore membranes, especially for those with sub-100 nm pores and low porosities.
Collapse
Affiliation(s)
- Jiakun Zhuang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, P. R. China.,Shenzhen Research Institute of Shandong University, Shenzhen, Guangdong, P. R. China
| | - Long Ma
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, P. R. China.,Shenzhen Research Institute of Shandong University, Shenzhen, Guangdong, P. R. China
| | - Yinghua Qiu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan, P. R. China.,Shenzhen Research Institute of Shandong University, Shenzhen, Guangdong, P. R. China.,Suzhou Research Institute, Shandong University, Suzhou, Jiangsu, P. R. China.,Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian, Liaoning, P. R. China
| |
Collapse
|
6
|
Ji A, Wang B, Xia G, Luo J, Deng Z. Effective Modulation of Ion Mobility through Solid-State Single-Digit Nanopores. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3946. [PMID: 36432237 PMCID: PMC9695415 DOI: 10.3390/nano12223946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/01/2022] [Accepted: 11/04/2022] [Indexed: 06/16/2023]
Abstract
Many experimental studies have proved that ion dynamics in a single-digit nanopore with dimensions comparable to the Debye length deviate from the bulk values, but we still have critical knowledge gaps in our understanding of ion transport in nanoconfinement. For many energy devices and sensor designs of nanoporous materials, ion mobility is a key parameter for the performance of nanofluidic equipment. However, investigating ion mobility remains an experimental challenge. This study experimentally investigated the monovalent ion dynamics of single-digit nanopores from the perspective of ionic conductance. In this article, we present a theory that is sufficient for a basic understanding of ion transport through a single-digit nanopore, and we subdivided and separately analyzed the contribution of each conductance component. These conclusions will be useful not only in understanding the behavior of ion migration but also in the design of high-performance nanofluidic devices.
Collapse
Affiliation(s)
- Anping Ji
- School of Mechanical Engineering, Chongqing Three Gorges University, Chongqing 404100, China
- Chongqing Engineering Technology Research Center for Light Alloy and Processing, Chongqing 404100, China
| | - Bo Wang
- School of Mechanical Engineering, Chongqing Three Gorges University, Chongqing 404100, China
| | - Guofeng Xia
- School of Mechanical Engineering, Chongqing Three Gorges University, Chongqing 404100, China
| | - Jinjie Luo
- School of Mechanical Engineering, Chongqing Three Gorges University, Chongqing 404100, China
- Chongqing Engineering Technology Research Center for Light Alloy and Processing, Chongqing 404100, China
| | - Zhenghua Deng
- School of Mechanical Engineering, Chongqing Three Gorges University, Chongqing 404100, China
- Chongqing Engineering Technology Research Center for Light Alloy and Processing, Chongqing 404100, China
| |
Collapse
|
7
|
Green Y. Electrical Conductance of Charged Nanopores. ACS OMEGA 2022; 7:36150-36156. [PMID: 36278037 PMCID: PMC9583083 DOI: 10.1021/acsomega.2c02266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
A nanopore's response to an electrical potential drop is characterized by its electrical conductance, . For the last two decades, it has been thought that at low electrolyte concentrations, , the conductance is concentration-independent such that . It has been recently demonstrated that surface charge regulation changes the dependency to , whereby the slope typically takes the values α = 1/3 or 1/2. However, experiments have observed slopes of 2/3 and 1 suggesting that additional mechanisms, such as convection and slip-lengths, appear. Here, we elucidate the interplay between three mechanisms: surface charge regulation, convection, and slip lengths. We show that the inclusion of convection does not change the slope, and when the effects of hydrodynamic slip are included, the slope is doubled. We show that when all effects are accounted for, α can take any value between 0 and 1 where the exact value of the slope depends on the material properties. This result is of utmost importance in designing any electro-kinetically driven nanofluidic system characterized by its conductance.
Collapse
|
8
|
The Dukhin number as a scaling parameter for selectivity in the infinitely long nanopore limit: Extension to multivalent electrolytes. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
9
|
Dong Y, Zhao Z, Zhao J, Guo Z, Du G, Sun Y, He D, Duan J, Liu J, Yao H. High-Performance Osmotic Power Generators Based on the 1D/2D Hybrid Nanochannel System. ACS APPLIED MATERIALS & INTERFACES 2022; 14:29197-29212. [PMID: 35704847 DOI: 10.1021/acsami.2c05247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Extracting clean energy by converting the salinity gradient between river and sea into energy is an effective way to reduce the global pollution and carbon emissions. Reverse electrodialysis (RED) is of great importance to realize the energy conversion assisting the ion-selective membrane. However, its higher ion resistance and lower conversion efficiency results in the undesirable power conversion performance. Here, we demonstrate a 1D/2D hybrid nanochannel system to achieve high osmotic energy conversion and output power. This heterogeneous structure is composed of two structures, in which the subnanometer nanochannels in graphene oxide membrane (GOM) can serve as a selective layer and reduce the ion diffusion energy barrier, while the nanochannel in the polymer can introduce asymmetry to enhance ionic rectification and conversion efficiency. This heterogeneous membrane exhibits excellent cation selectivity and enhanced ionic current rectification (ICR) performance. The application of the GOM/PET hybrid nanochannel system in osmotic energy harvesting is evaluated, and the output power can reach up to 118.2 pW with the energy conversion efficiency of 40.3%. Theoretical calculation indicates that the 1D/2D hybrid system can effectively take the advantage of excellent cation selectivity of 2D lamellar nanochannels to improve its RED performance significantly.
Collapse
Affiliation(s)
- Yuhua Dong
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Zhuo Zhao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Jing Zhao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Zaichao Guo
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Guanghua Du
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Youmei Sun
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Deyan He
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou730000, PR China
| | - Jinglai Duan
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou516000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Jie Liu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| | - Huijun Yao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou730000, PR China
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou516000, PR China
- University of Chinese Academy of Sciences, Beijing100049, PR China
| |
Collapse
|
10
|
Neklyudov V, Freger V. Putting together the puzzle of ion transfer in single-digit carbon nanotubes: mean-field meets ab initio. NANOSCALE 2022; 14:8677-8690. [PMID: 35671158 DOI: 10.1039/d1nr08073c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nature employs channel proteins to selectively pass water across cell membranes, which inspires the search for bio-mimetic analogues. Carbon nanotube porins (CNTPs) are intriguing mimics of water channels, yet ion transport in CNTPs still poses questions. As an alternative to continuum models, here we present a molecular mean-field model that transparently describes ion coupling, yet unlike continuum models, computes ab initio all required thermodynamic quantities for the KCl salt and H+ and OH- ions present in water. Starting from water transfer, the model considers the transfer of free ions, along with ion-pair formation as a proxy of non-mean-field ion-ion interactions. High affinity to hydroxide, suggested by experiments, making it a dominant charge carrier in CNTPs, is revealed as an exceptionally favorable transfer of KOH pairs. Nevertheless, free ions, coexisting with less mobile ion-pairs, apparently control ion transport. The model well explains the observed effects of salt concentration and pH on conductivity, transport numbers, anion permeation and its activation energies, and current rectification. The proposed approach is extendable to other sub-nanochannels and helps design novel osmotic materials and devices.
Collapse
Affiliation(s)
- Vadim Neklyudov
- Wolfson Department of Chemical Engineering, Technion - IIT, Haifa 32000, Israel.
| | - Viatcheslav Freger
- Wolfson Department of Chemical Engineering, Technion - IIT, Haifa 32000, Israel.
- Russel Berrie Nanotechnology Institute, Technion - IIT, Haifa 32000, Israel
- Grand Technion Energy Program, Technion - IIT, Haifa 32000, Israel
| |
Collapse
|
11
|
Zhang X, Xu M, Yang J, Hu N. Ion Transport in pH-Regulated Double-Barreled Nanopores. Anal Chem 2022; 94:5642-5650. [PMID: 35352923 DOI: 10.1021/acs.analchem.1c05654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Single-molecule detection and characterization with nanopores is a powerful technique that does not require labeling. Multinanopore systems, especially double nanopores, have attracted wide attention and have been applied in many fields. However, theoretical studies of electrokinetic ion transport in nanopores mainly focus on single nanopores. In this paper, for the first time, a theoretical study of pH-regulated double-barreled nanopores is conducted using three-dimensional Poisson-Nernst-Planck equations and Navier-Stokes equations. Four ionic species and the surface chemistry on the walls of the nanopores are included. The results demonstrate that the properties of the bulk salt solution significantly affect nanopore conductivity and ion transport phenomena in nanopores. There are two ion-enriched zones and two ion-depleted zones in double-barreled nanopores. Due to the symmetry of the double-barreled nanopore structure and surface charge density, there is no ionic rectification effect in double-barreled nanopores. The ion selectivity is similar to that of conventional single pH-regulated nanopores.
Collapse
Affiliation(s)
- Xiaoling Zhang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400030, P. R. China.,Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, P. R. China.,Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, P. R. China
| | - Mengli Xu
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400030, P. R. China
| | - Jun Yang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400030, P. R. China
| | - Ning Hu
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400030, P. R. China
| |
Collapse
|
12
|
Jiang X, Zhao C, Noh Y, Xu Y, Chen Y, Chen F, Ma L, Ren W, Aluru NR, Feng J. Nonlinear electrohydrodynamic ion transport in graphene nanopores. SCIENCE ADVANCES 2022; 8:eabj2510. [PMID: 35030026 PMCID: PMC8759738 DOI: 10.1126/sciadv.abj2510] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/22/2021] [Indexed: 05/25/2023]
Abstract
Mechanosensitivity is one of the essential functionalities of biological ion channels. Synthesizing an artificial nanofluidic system to mimic such sensations will not only improve our understanding of these fluidic systems but also inspire applications. In contrast to the electrohydrodynamic ion transport in long nanoslits and nanotubes, coupling hydrodynamical and ion transport at the single-atom thickness remains challenging. Here, we report the pressure-modulated ion conduction in graphene nanopores featuring nonlinear electrohydrodynamic coupling. Increase of ionic conductance, ranging from a few percent to 204.5% induced by the pressure—an effect that was not predicted by the classical linear coupling of molecular streaming to voltage-driven ion transport—was observed experimentally. Computational and theoretical studies reveal that the pressure sensitivity of graphene nanopores arises from the transport of capacitively accumulated ions near the graphene surface. Our findings may help understand the electrohydrodynamic ion transport in nanopores and offer a new ion transport controlling methodology.
Collapse
Affiliation(s)
- Xiaowei Jiang
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Chunxiao Zhao
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yang Xu
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yuang Chen
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Fanfan Chen
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Laipeng Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Narayana R. Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas, TX 78712, USA
| | - Jiandong Feng
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| |
Collapse
|
13
|
Abstract
It has recently been suggested that a breakdown of electroneutrality occurs in highly confined nanopores that are encompassed by a dielectric material. This work elucidates the conditions for this breakdown. We show that the breakdown within the pore results from the response of the electric field within the dielectric. Namely, we show that this response is highly sensitive to the boundary condition at the dielectric edge. The standard Neumann boundary condition of no-flux predicts that the breakdown does not occur. However, a Dirichlet boundary condition for a zero-potential predicts a breakdown. Within this latter scenario, the breakdown exhibits a dependence on the thickness of the dielectric material. Specifically, infinite thickness dielectrics do not exhibit a breakdown, while dielectrics of finite thickness do exhibit a breakdown. Numerical simulations confirm theoretical predictions. The breakdown outcomes are discussed with regard to single pore systems and multiple pore systems.
Collapse
Affiliation(s)
- Yoav Green
- Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| |
Collapse
|
14
|
Joly L, Meißner RH, Iannuzzi M, Tocci G. Osmotic Transport at the Aqueous Graphene and hBN Interfaces: Scaling Laws from a Unified, First-Principles Description. ACS NANO 2021; 15:15249-15258. [PMID: 34491721 DOI: 10.1021/acsnano.1c05931] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Osmotic transport in nanoconfined aqueous electrolytes provides alternative venues for water desalination and "blue energy" harvesting. The osmotic response of nanofluidic systems is controlled by the interfacial structure of water and electrolyte solutions in the so-called electrical double layer (EDL), but a molecular-level picture of the EDL is to a large extent still lacking. Particularly, the role of the electronic structure has not been considered in the description of electrolyte/surface interactions. Here, we report enhanced sampling simulations based on ab initio molecular dynamics, aiming at unravelling the free energy of prototypical ions adsorbed at the aqueous graphene and hBN interfaces, and its consequences on nanofluidic osmotic transport. Specifically, we predicted the zeta potential, the diffusio-osmotic mobility, and the diffusio-osmotic conductivity for a wide range of salt concentrations from the ab initio water and ion spatial distributions through an analytical framework based on Stokes equation and a modified Poisson-Boltzmann equation. We observed concentration-dependent scaling laws, together with dramatic differences in osmotic transport between the two interfaces, including diffusio-osmotic flow and current reversal on hBN but not on graphene. We could rationalize the results for the three osmotic responses with a simple model based on characteristic length scales for ion and water adsorption at the surface, which are quite different on graphene and on hBN. Our work provides fundamental insights into the structure and osmotic transport of aqueous electrolytes on 2D materials and explores alternative pathways for efficient water desalination and osmotic energy conversion.
Collapse
Affiliation(s)
- Laurent Joly
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
- Institut Universitaire de France (IUF), 1 rue Descartes, 75005 Paris, France
| | - Robert H Meißner
- Hamburg University of Technology, Insitute of Polymers and Composites, Hamburg 21073, Germany
- Helmholtz-Zentrum Hereon, Institute of Surface Science, Geesthacht 21502, Germany
| | - Marcella Iannuzzi
- Department of Chemistry, Universität Zürich, 8057 Zürich, Switzerland
| | - Gabriele Tocci
- Department of Chemistry, Universität Zürich, 8057 Zürich, Switzerland
| |
Collapse
|
15
|
Lin K, Li Z, Tao Y, Li K, Yang H, Ma J, Li T, Sha J, Chen Y. Surface Charge Density Inside a Silicon Nitride Nanopore. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:10521-10528. [PMID: 34347494 DOI: 10.1021/acs.langmuir.1c01504] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Surface charges inside a nanopore determine the zeta potential and ion distributions and play a significant role in affecting ion transport and the sensitivity of detecting biomolecules. It is of great importance to study the fluctuation of surface charges with the salt concentration and pH in various applications of nanopores. Herein, we proposed a theoretical model to predict the surface charge density of a Si3N4 nanopore, in which both silanol and amine groups were taken into account. It was demonstrated that the surface charge density in the Si3N4 nanopore changes not only with pH but also with the salt concentration. The theoretical model could well predict the experimental results with different salt concentrations, pH values, and pore sizes. The effect of surface functional groups on the isopotential point (pHiep) of the Si3N4 nanopore was also systematically studied. The results indicated that the silanol groups are major determinants of the surface charge, but the influences of the amine groups should not be ignored because the small number of amine groups can change pHiep dramatically. The pHiep value of the Si3N4 nanopore was measured as 4.1, and the ratio of amine over silanol was ascertained as 0.013.
Collapse
Affiliation(s)
- Kabin Lin
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Zhongwu Li
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Yi Tao
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Kun Li
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Haojie Yang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Jian Ma
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Tie Li
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
| | - Jingjie Sha
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | - Yunfei Chen
- Jiangsu Key Laboratory for Design and Manufacture of Micro-nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| |
Collapse
|
16
|
Yao YC, Li Z, Gillen AJ, Yosinski S, Reed MA, Noy A. Electrostatic gating of ion transport in carbon nanotube porins: A modeling study. J Chem Phys 2021; 154:204704. [PMID: 34241182 DOI: 10.1063/5.0049550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Carbon nanotube porins (CNTPs) are biomimetic membrane channels that demonstrate excellent biocompatibility and unique water and ion transport properties. Gating transport in CNTPs with external voltage could increase control over ion flow and selectivity. Herein, we used continuum modeling to probe the parameters that enable and further affect CNTP gating efficiency, including the size and composition of the supporting lipid membrane, slip flow in the carbon nanotube, and the intrinsic electronic properties of the nanotube. Our results show that the optimal gated CNTP device consists of a semiconducting CNTP inserted into a small membrane patch containing an internally conductive layer. Moreover, we demonstrate that the ionic transport modulated by gate voltages is controlled by the charge distribution along the CNTP under the external gate electric potential. The theoretical understanding developed in this study offers valuable guidance for the design of gated CNTP devices for nanofluidic studies, novel biomimetic membranes, and cellular interfaces in the future.
Collapse
Affiliation(s)
- Yun-Chiao Yao
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Zhongwu Li
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Alice J Gillen
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Shari Yosinski
- Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520, USA
| | - Mark A Reed
- Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520, USA
| | - Aleksandr Noy
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| |
Collapse
|
17
|
Fertig D, Sarkadi Z, Valiskó M, Boda D. Scaling for rectification of bipolar nanopores as a function of a modified Dukhin number: the case of 1:1 electrolytes. MOLECULAR SIMULATION 2021. [DOI: 10.1080/08927022.2021.1939330] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Dávid Fertig
- Center for Natural Sciences, University of Pannonia, Veszprém, Hungary
| | - Zsófia Sarkadi
- Center for Natural Sciences, University of Pannonia, Veszprém, Hungary
| | - Mónika Valiskó
- Center for Natural Sciences, University of Pannonia, Veszprém, Hungary
| | | |
Collapse
|
18
|
Abu-Rjal R, Green Y. Bipolar Nanochannels: A Systematic Approach to Asymmetric Problems. ACS APPLIED MATERIALS & INTERFACES 2021; 13:27622-27634. [PMID: 34080433 DOI: 10.1021/acsami.1c05643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nanofluidic diodes are capable of rectifying the electrical current by several orders of magnitude. In the current state of affairs, determining the rectification factor is not possible as it depends on many system parameters. In this work, we systematically scan the effects of geometry and excess counterion concentrations (i.e., surface charge effects). We show that the current-voltage response varies between the two extreme behaviors of unipolar and bipolar responses. The exact behavior depends on the geometry and surface charge properties of the system. Here, we have gone beyond the typical setup that only considers the dynamics within the nanochannel itself and we have included the effects of the adjoining microchannels. Systems that include both nanochannels and microchannels exhibit the classical signatures of concentration polarization, such as ionic depletion and enrichment. Here, where we have scanned a wide range of parameters, we show that bipolar and semi-bipolar systems exhibit a wider range of phenomena that are intrinsically more complicated. Our system characterization is for both, the much more investigated case of steady state and the less investigated, but equally interesting, time-transient case. For example, it is common to characterize the system by its steady-state result (current-voltage response, rectification factor, and transport number). Here, we demonstrate that the time-transient behavior of the fluxes can also be used to characterize the system, and that the time-dependent rectification factors and transport numbers are meaningful. The systematic approach taken in this work, and the results presented herein, can be used to further elucidate the complicated behavior of the current-voltage response of nanofluidic diodes and to rationalize experimental results. The insights of this work can be used to enhance and improve the design of all nanofluidic diodes.
Collapse
Affiliation(s)
- Ramadan Abu-Rjal
- Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Faculty of Mechanical Engineering, Micro- and Nanofluidics Laboratory, Technion-Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Yoav Green
- Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| |
Collapse
|
19
|
Sarkadi Z, Fertig D, Ható Z, Valiskó M, Boda D. From nanotubes to nanoholes: Scaling of selectivity in uniformly charged nanopores through the Dukhin number for 1:1 electrolytes. J Chem Phys 2021; 154:154704. [PMID: 33887923 DOI: 10.1063/5.0040593] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Scaling of the behavior of a nanodevice means that the device function (selectivity) is a unique smooth and monotonic function of a scaling parameter that is an appropriate combination of the system's parameters. For the uniformly charged cylindrical nanopore studied here, these parameters are the electrolyte concentration, c, voltage, U, the radius and the length of the nanopore, R and H, and the surface charge density on the nanopore's surface, σ. Due to the non-linear dependence of selectivities on these parameters, scaling can only be applied in certain limits. We show that the Dukhin number, Du=|σ|/eRc∼|σ|λD 2/eR (λD is the Debye length), is an appropriate scaling parameter in the nanotube limit (H → ∞). Decreasing the length of the nanopore, namely, approaching the nanohole limit (H → 0), an alternative scaling parameter has been obtained, which contains the pore length and is called the modified Dukhin number: mDu ∼ Du H/λD ∼ |σ|λDH/eR. We found that the reason for non-linearity is that the double layers accumulating at the pore wall in the radial dimension correlate with the double layers accumulating at the entrances of the pore near the membrane on the two sides. Our modeling study using the Local Equilibrium Monte Carlo method and the Poisson-Nernst-Planck theory provides concentration, flux, and selectivity profiles that show whether the surface or the volume conduction dominates in a given region of the nanopore for a given combination of the variables. We propose that the inflection point of the scaling curve may be used to characterize the transition point between the surface and volume conductions.
Collapse
Affiliation(s)
- Zsófia Sarkadi
- Center for Natural Sciences, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
| | - Dávid Fertig
- Center for Natural Sciences, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
| | - Zoltán Ható
- Center for Natural Sciences, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
| | - Mónika Valiskó
- Center for Natural Sciences, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
| | - Dezső Boda
- Center for Natural Sciences, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
| |
Collapse
|
20
|
Ji A, Chen Y. Electric control of ionic transport in sub-nm nanopores. RSC Adv 2021; 11:13806-13813. [PMID: 35423930 PMCID: PMC8697696 DOI: 10.1039/d1ra01089a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/30/2021] [Indexed: 11/21/2022] Open
Abstract
The ion transport behavior through sub-nm nanopores (length (L) ≈ radius (R)) on a film is different from that in nanochannels (L ≫ R), and even more different from the bulk behavior. The many intriguing phenomena in ionic transport are the key to the design and fabrication of solid-state nanofluidic devices. However, ion transport through sub-nm nanopores is not yet clearly understood. We investigate the ionic transport behavior of sub-nm nanopores from the perspective of conductance via molecular dynamics (MD) and experimental methods. Under the action of surface charge, the average ion concentration inside the nanopore is much higher than the bulk value. It is found that 100 mM is the transition point between the surface-charge-governed and the bulk behavior regimes, which is different from the transition point for nanochannels (10 mM). Moreover, by investigating the access, pores, surface charge, electroosmosis and potential leakage conductance, it is found that the conductive properties of the nanopore at low bulk concentration are determined by the surface charge potential leaks into the reservoir. Specifically, there is a huge increase in cation mobility through a cylindrical nanopore, which implies potential applications for the fast charging of supercapacitors and batteries. Sub-nm nanopores also show a strong selectivity toward Na+, and a strong repellence toward Cl−. These conclusions presented here will be useful not only in understanding the behavior of ion transport, but also in the design of nanofluidic devices. The ion transport behavior through sub-nm nanopores (length (L) ≈ radius (R)) on a film is different from that in nanochannels (L ≫ R), and even more different from the bulk behavior.![]()
Collapse
Affiliation(s)
- Anping Ji
- School of Mechanical Engineering
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments
- Southeast University
- Nanjing
- China
| | - Yunfei Chen
- School of Mechanical Engineering
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments
- Southeast University
- Nanjing
- China
| |
Collapse
|