1
|
Shoemaker BA, Haji-Akbari A. Ideal conductor/dielectric model (ICDM): A generalized technique to correct for finite-size effects in molecular simulations of hindered ion transport. J Chem Phys 2024; 160:024116. [PMID: 38197447 DOI: 10.1063/5.0180029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/18/2023] [Indexed: 01/11/2024] Open
Abstract
Molecular simulations serve as indispensable tools for investigating the kinetics and elucidating the mechanism of hindered ion transport across nanoporous membranes. In particular, recent advancements in advanced sampling techniques have made it possible to access translocation timescales spanning several orders of magnitude. In our prior study [Shoemaker et al., J. Chem. Theory Comput. 18, 7142 (2022)], we identified significant finite size artifacts in simulations of pressure-driven hindered ion transport through nanoporous graphitic membranes. We introduced the ideal conductor model, which effectively corrects for such artifacts by assuming the feed to be an ideal conductor. In the present work, we introduce the ideal conductor dielectric model (Icdm), a generalization of our earlier model, which accounts for the dielectric properties of both the membrane and the filtrate. Using the Icdm model substantially enhances the agreement among corrected free energy profiles obtained from systems of varying sizes, with notable improvements observed in regions proximate to the pore exit. Moreover, the model has the capability to consider secondary ion passage events, including the transport of a co-ion subsequent to the traversal of a counter-ion, a feature that is absent in our original model. We also investigate the sensitivity of the new model to various implementation details. The Icdm model offers a universally applicable framework for addressing finite size artifacts in molecular simulations of ion transport. It stands as a significant advancement in our quest to use molecular simulations to comprehensively understand and manipulate ion transport processes through nanoporous membranes.
Collapse
Affiliation(s)
- Brian A Shoemaker
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, USA
| | - Amir Haji-Akbari
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, USA
| |
Collapse
|
2
|
Gomez CG, Linarez Pérez OE, Avalle LB, Rojas MI. Morphological and electrochemical characterizations of a carbon nitride/highly oriented pyrolytic graphite electrode. J Electroanal Chem (Lausanne) 2021. [DOI: 10.1016/j.jelechem.2021.115621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
3
|
Sun Y, Li Y. Application of surface complexation modeling on adsorption of uranium at water-solid interface: A review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 278:116861. [PMID: 33714063 DOI: 10.1016/j.envpol.2021.116861] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/17/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
Precise prediction of uranium adsorption at water-mineral interface is of great significance for the safe disposal of radionuclides in geologic environments. Surface complexation modeling (SCM) as a very useful tool has been extensively investigated for simulating adsorption behavior of metals/metalloids at water-mineral interface. Numerous studies concerning the fitting of uranium adsorption on various adsorbents using SCM are well documented, but the systematic and comprehensive review of uranium adsorption using various SCM is not available. In this review, we briefly summarized the rationale of SCM, including constant-capacitance-model (CCM), diffuse-layer-model (DLM), triple-layer-model (TLM); The recent progress in the application of SCM on the fitting of uranium adsorption towards metal (hydr)oxides, clay minerals and soil/sediments was reviewed in details. This review hopefully provides the beneficial guidelines for predicting the transport and fate of uranium in geologic environments beyond laboratory timescales.
Collapse
Affiliation(s)
- Yubing Sun
- College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, PR China.
| | - Ying Li
- College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, PR China
| |
Collapse
|
4
|
Panahi A, Sadighbayan D, Forouhi S, Ghafar-Zadeh E. Recent Advances of Field-Effect Transistor Technology for Infectious Diseases. BIOSENSORS 2021; 11:103. [PMID: 33918325 PMCID: PMC8065562 DOI: 10.3390/bios11040103] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 02/07/2023]
Abstract
Field-effect transistor (FET) biosensors have been intensively researched toward label-free biomolecule sensing for different disease screening applications. High sensitivity, incredible miniaturization capability, promising extremely low minimum limit of detection (LoD) at the molecular level, integration with complementary metal oxide semiconductor (CMOS) technology and last but not least label-free operation were amongst the predominant motives for highlighting these sensors in the biosensor community. Although there are various diseases targeted by FET sensors for detection, infectious diseases are still the most demanding sector that needs higher precision in detection and integration for the realization of the diagnosis at the point of care (PoC). The COVID-19 pandemic, nevertheless, was an example of the escalated situation in terms of worldwide desperate need for fast, specific and reliable home test PoC devices for the timely screening of huge numbers of people to restrict the disease from further spread. This need spawned a wave of innovative approaches for early detection of COVID-19 antibodies in human swab or blood amongst which the FET biosensing gained much more attention due to their extraordinary LoD down to femtomolar (fM) with the comparatively faster response time. As the FET sensors are promising novel PoC devices with application in early diagnosis of various diseases and especially infectious diseases, in this research, we have reviewed the recent progress on developing FET sensors for infectious diseases diagnosis accompanied with a thorough discussion on the structure of Chem/BioFET sensors and the readout circuitry for output signal processing. This approach would help engineers and biologists to gain enough knowledge to initiate their design for accelerated innovations in response to the need for more efficient management of infectious diseases like COVID-19.
Collapse
Affiliation(s)
- Abbas Panahi
- Biologically Sensors and Actuators (BioSA) Laboratory, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada; (A.P.); (D.S.); (S.F.)
- Department of Electrical Engineering and Computer Science, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada
| | - Deniz Sadighbayan
- Biologically Sensors and Actuators (BioSA) Laboratory, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada; (A.P.); (D.S.); (S.F.)
- Department of Biology, Faculty of Science, York University, Keel Street, Toronto, ON M3J 1P3, Canada
| | - Saghi Forouhi
- Biologically Sensors and Actuators (BioSA) Laboratory, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada; (A.P.); (D.S.); (S.F.)
- Department of Electrical Engineering and Computer Science, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada
| | - Ebrahim Ghafar-Zadeh
- Biologically Sensors and Actuators (BioSA) Laboratory, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada; (A.P.); (D.S.); (S.F.)
- Department of Electrical Engineering and Computer Science, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada
- Department of Biology, Faculty of Science, York University, Keel Street, Toronto, ON M3J 1P3, Canada
| |
Collapse
|
5
|
Kłos J, Lamperski S. Influence of electrical images and electrolyte concentration on capacitance of the electrode - molten salt interface. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.137720] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
6
|
Drab M, Gongadze E, Kralj-Iglič V, Iglič A. Electric Double Layer and Orientational Ordering of Water Dipoles in Narrow Channels within a Modified Langevin Poisson-Boltzmann Model. ENTROPY (BASEL, SWITZERLAND) 2020; 22:E1054. [PMID: 33286823 PMCID: PMC7597128 DOI: 10.3390/e22091054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/04/2020] [Accepted: 09/18/2020] [Indexed: 02/05/2023]
Abstract
The electric double layer (EDL) is an important phenomenon that arises in systems where a charged surface comes into contact with an electrolyte solution. In this work we describe the generalization of classic Poisson-Boltzmann (PB) theory for point-like ions by taking into account orientational ordering of water molecules. The modified Langevin Poisson-Boltzmann (LPB) model of EDL is derived by minimizing the corresponding Helmholtz free energy functional, which includes also orientational entropy contribution of water dipoles. The formation of EDL is important in many artificial and biological systems bound by a cylindrical geometry. We therefore numerically solve the modified LPB equation in cylindrical coordinates, determining the spatial dependencies of electric potential, relative permittivity and average orientations of water dipoles within charged tubes of different radii. Results show that for tubes of a large radius, macroscopic (net) volume charge density of coions and counterions is zero at the geometrical axis. This is attributed to effective electrolyte charge screening in the vicinity of the inner charged surface of the tube. For tubes of small radii, the screening region extends into the whole inner space of the tube, leading to non-zero net volume charge density and non-zero orientational ordering of water dipoles near the axis.
Collapse
Affiliation(s)
- Mitja Drab
- Faculty of Electrical Engineering, Tržaška Cesta 25, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.D.); (E.G.)
| | - Ekaterina Gongadze
- Faculty of Electrical Engineering, Tržaška Cesta 25, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.D.); (E.G.)
| | - Veronika Kralj-Iglič
- Faculty of Health Sciences, Zdravstvena Pot 5, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
| | - Aleš Iglič
- Faculty of Electrical Engineering, Tržaška Cesta 25, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.D.); (E.G.)
| |
Collapse
|
7
|
Kłos J, Lamperski S. Electrical double layer in molten salts taking into account Lennard-Jones potential. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.135747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
8
|
Starch as a Green Binder for the Formulation of Conducting Glue in Supercapacitors. Polymers (Basel) 2019; 11:polym11101648. [PMID: 31614451 PMCID: PMC6836256 DOI: 10.3390/polym11101648] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/07/2019] [Accepted: 10/09/2019] [Indexed: 11/17/2022] Open
Abstract
This work describes the use of commercially available starch as a binder for the preparation of conductive glue and electrode materials. It is demonstrated that starch can be successfully implemented as a binder in energy storage systems with non-aqueous electrolytes. These devices are characterized by a stable cycle life (for 50,000 cycles) at a nominal voltage of 2.5 V. Moreover, the use of starch-based conductive glue improves the electrochemical performance, especially reducing the internal resistance of the device. Starch-bound electrodes display lower equivalent distributed resistance (EDR) values than electrodes using carboxymethylcellulose (CMC) as the binder. This is due to the noticeably lower pore clogging by starch. An electric double-layer capacitor (EDLC) in organic electrolyte (1 mol L−1 TEABF4 in ACN) at a nominal voltage of 2.5 V can reach a specific power and energy of 100 kW kg−1 and 12 Wh kg −1, respectively. This study shows that starch-based conductive glues and electrode materials can be incorporated in EDLC systems.
Collapse
|
9
|
Dos Santos AP, Girotto M, Levin Y. Simulations of Coulomb systems confined by polarizable surfaces using periodic Green functions. J Chem Phys 2018; 147:184105. [PMID: 29141417 DOI: 10.1063/1.4997420] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present an efficient approach for simulating Coulomb systems confined by planar polarizable surfaces. The method is based on the solution of the Poisson equation using periodic Green functions. It is shown that the electrostatic energy arising from the surface polarization can be decoupled from the energy due to the direct Coulomb interaction between the ions. This allows us to combine an efficient Ewald summation method, or any other fast method for summing over the replicas, with the polarization contribution calculated using Green function techniques. We apply the method to calculate density profiles of ions confined between the charged dielectric and metal surfaces.
Collapse
Affiliation(s)
- Alexandre P Dos Santos
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| | - Matheus Girotto
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| | - Yan Levin
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| |
Collapse
|
10
|
Effects of Alkyl Chain Length on Interfacial Structure and Differential Capacitance in Graphene Supercapacitors: A Molecular Dynamics Simulation Study. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.06.169] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
11
|
dos Santos AP, Girotto M, Levin Y. Simulations of Polyelectrolyte Adsorption to a Dielectric Like-Charged Surface. J Phys Chem B 2016; 120:10387-10393. [DOI: 10.1021/acs.jpcb.6b06002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Alexandre P. dos Santos
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| | - Matheus Girotto
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| | - Yan Levin
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| |
Collapse
|
12
|
Lebar AM, Velikonja A, Kramar P, Iglič A. Internal configuration and electric potential in planar negatively charged lipid head group region in contact with ionic solution. Bioelectrochemistry 2016; 111:49-56. [PMID: 27209203 DOI: 10.1016/j.bioelechem.2016.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 04/19/2016] [Accepted: 04/19/2016] [Indexed: 11/17/2022]
Abstract
The lipid bilayer composed of negatively charged lipid 1-palmitoyl-3-oleoyl-sn-glycero-3-phosphatidylserine (POPS) in contact with an aqueous solution of monovalent salt ions was studied theoretically by using the mean-field modified Langevin-Poisson-Boltzmann (MLPB) model. The MLPB results were tested by using molecular dynamic (MD) simulations. In the MLPB model the charge distribution of POPS head groups is theoretically described by the negatively charged surface which accounts for negatively charged phosphate groups, while the positively charged amino groups and negatively charged carboxylate groups are assumed to be fixed on the rod-like structures with rotational degree of freedom. The spatial variation of relative permittivity, which is not considered in the well-known Gouy-Chapman (GC) model or in MD simulations, is thoroughly derived within a strict statistical mechanical approach. Therefore, the spatial dependence and magnitude of electric potential within the lipid head group region and its close vicinity are considerably different in the MLPB model from the GC model. The influence of the bulk salt concentration and temperature on the number density profiles of counter-ions and co-ions in the lipid head group region and aqueous solution along with the probability density function for the lipid head group orientation angle was compared and found to be in qualitative agreement in the MLPB and MD models.
Collapse
Affiliation(s)
- Alenka Maček Lebar
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia
| | - Aljaž Velikonja
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia
| | - Peter Kramar
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia
| | - Aleš Iglič
- Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia.
| |
Collapse
|
13
|
Gongadze E, Iglič A. Asymmetric size of ions and orientational ordering of water dipoles in electric double layer model - an analytical mean-field approach. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.07.179] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
14
|
Abstract
Capacitive energy storage devices are receiving increasing experimental and theoretical attention due to their enormous potential for energy applications. Current research in this field is focused on the improvement of both the energy and the power density of supercapacitors by optimizing the nanostructure of porous electrodes and the chemical structure/composition of the electrolytes. However, the understanding of the underlying correlations and the mechanisms of electric double layer formation near charged surfaces and inside nanoporous electrodes is complicated by the complex interplay of several molecular scale phenomena. This Perspective presents several aspects regarding the experimental and theoretical research in the field, discusses the current atomistic and molecular scale understanding of the mechanisms of energy and charge storage, and provides a brief outlook to the future developments and applications of these devices.
Collapse
Affiliation(s)
- Jenel Vatamanu
- Department of Materials Science & Engineering, The University of Utah , 122 S. Central Campus Drive, Salt Lake City, Utah 84112, United States
| | - Dmitry Bedrov
- Department of Materials Science & Engineering, The University of Utah , 122 S. Central Campus Drive, Salt Lake City, Utah 84112, United States
| |
Collapse
|
15
|
Nagy T, Henderson D, Boda D. Correction to “Simulation of an Electrical Double Layer Model with a Low Dielectric Layer between the Electrode and the Electrolyte”. J Phys Chem B 2015; 119:11967-8. [DOI: 10.1021/acs.jpcb.5b07719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
dos Santos AP, Levin Y. Electrolytes between dielectric charged surfaces: Simulations and theory. J Chem Phys 2015; 142:194104. [PMID: 26001444 DOI: 10.1063/1.4921221] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
We present a simulation method to study electrolyte solutions in a dielectric slab geometry using a modified 3D Ewald summation. The method is fast and easy to implement, allowing us to rapidly resum an infinite series of image charges. In the weak coupling limit, we also develop a mean-field theory which allows us to predict the ionic distribution between the dielectric charged plates. The agreement between both approaches, theoretical and simulational, is very good, validating both methods. Examples of ionic density profiles in the strong electrostatic coupling limit are also presented. Finally, we explore the confinement of charge asymmetric electrolytes between neutral surfaces.
Collapse
Affiliation(s)
- Alexandre P dos Santos
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS, Brazil
| | - Yan Levin
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS, Brazil
| |
Collapse
|
17
|
Lamperski S, Płuciennik M, Outhwaite CW. The planar electric double layer capacitance for the solvent primitive model electrolyte. Phys Chem Chem Phys 2015; 17:928-32. [DOI: 10.1039/c4cp03513e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The transition of the solvent primitive model electrolyte differential capacitance from a minimum to a maximum, at fixed total packing fraction, occurs at a higher electrolyte concentration than that of the restricted primitive model electrolyte.
Collapse
Affiliation(s)
- Stanisław Lamperski
- Department of Physical Chemistry
- Faculty of Chemistry
- Adam Mickiewicz University in Poznań
- 61-614 Poznań
- Poland
| | - Monika Płuciennik
- Department of Physical Chemistry
- Faculty of Chemistry
- Adam Mickiewicz University in Poznań
- 61-614 Poznań
- Poland
| | | |
Collapse
|
18
|
Outhwaite CW, Bhuiyan LB. The point ion modified Poisson–Boltzmann theory for a planar electric double layer with different permittivities for the electrode, inner layer and diffuse layer. Mol Phys 2014. [DOI: 10.1080/00268976.2014.922706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
19
|
Gongadze E, Velikonja A, Perutkova Š, Kramar P, Maček-Lebar A, Kralj-Iglič V, Iglič A. Ions and water molecules in an electrolyte solution in contact with charged and dipolar surfaces. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2013.07.147] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
20
|
Kant R, Singh MB. Generalization of the Gouy-Chapman-Stern model of an electric double layer for a morphologically complex electrode: deterministic and stochastic morphologies. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:052303. [PMID: 24329260 DOI: 10.1103/physreve.88.052303] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 09/21/2013] [Indexed: 06/03/2023]
Abstract
We generalize the linearized Gouy-Chapman-Stern theory of an electric double layer for morphologically complex and disordered electrodes. An equation for capacitance is obtained using a linear Gouy-Chapman or Debye-Hückel equation for the potential near the complex-geometry electrode-electrolyte interface. The effect of the surface morphology of an electrode on an electric double layer is obtained using multiple scattering formalism in surface curvature. The result for capacitance is expressed in terms of the ratio of Gouy screening length to the local principal radii of curvatures of the surface. We also include a contribution of a compact layer, which is significant in the overall prediction of capacitance. Our general results are analyzed in detail for two special morphologies of electrodes, i.e., a nanoporous membrane and a forest of nanopillars. Variations of local shapes and global size variations due to residual randomness in morphology are accounted for as curvature fluctuations over a reference shape element. In particular, the theory shows that the presence of geometrical fluctuations in porous systems causes an enhanced dependence of capacitance on mean pore sizes and suppresses the magnitude of capacitance. This theory is further extended to include contributions to capacitance from adsorption of ions and electrode material due to electronic screening. Our predictions are in reasonable agreement with recent experimental measurements on supercapacitive microporous and mesoporous systems.
Collapse
Affiliation(s)
- Rama Kant
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | | |
Collapse
|
21
|
The quadrupole moment of water molecules and the permittivity of water near a charged surface. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.07.126] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
22
|
Hu Z, Vatamanu J, Borodin O, Bedrov D. A molecular dynamics simulation study of the electric double layer and capacitance of [BMIM][PF6] and [BMIM][BF4] room temperature ionic liquids near charged surfaces. Phys Chem Chem Phys 2013; 15:14234-47. [DOI: 10.1039/c3cp51218e] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
23
|
Wang ZY, Ma YQ. A molecular simulation study on the role of ion sizes and dielectric images in near-surface ion distribution far from the strong coupling limit. J Chem Phys 2012; 136:234701. [DOI: 10.1063/1.4729311] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
|
24
|
Wang ZY, Ma YQ. Computational evidence of two driving mechanisms for overcharging in an electric double layer near the point of zero charge. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:062501. [PMID: 23005151 DOI: 10.1103/physreve.85.062501] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 03/26/2012] [Indexed: 06/01/2023]
Abstract
We have adopted an ensemble Monte Carlo simulation method to systematically verify two physical driving mechanisms responsible for overcharging which refers to the adsorption of an effective charge onto a like-charged planar surface around the point of zero charge within the primitive model of mixed electrolytes with varying salt concentrations. One is electrostatic in character dominated by dielectric images and the other is purely entropic in origin by ionic size asymmetry effects, of which the former has never been reported both theoretically and experimentally and the latter could be interpreted satisfactorily in terms of available theoretical approaches. The electrostatically driven mechanism is found to critically depend on the ionic sizes while the entropically driven mechanism occurs with almost the same efficiency in a relative wide range of surface charge density. Depending on the delicate interplay between charge and steric correlations, the two distinct driving mechanisms may cooperatively give rise to a more pronounced overcharging process.
Collapse
Affiliation(s)
- Zhi-Yong Wang
- School of Optoelectronic Information, Chongqing University of Technology, Chongqing 400054, China.
| | | |
Collapse
|