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Winarto, Yamamoto E, Yasuoka K. Water molecules in CNT-Si 3N 4 membrane: Properties and the separation effect for water-alcohol solution. J Chem Phys 2021; 155:104701. [PMID: 34525818 DOI: 10.1063/5.0055027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Water confined in carbon nanotubes (CNTs) has been intensively studied because of its unique properties and potential for various applications and is often embedded in silicon nitride (Si3N4) membranes. However, the understanding of the influence of Si3N4 on the properties of water in CNTs lacks clarity. In this study, we performed molecular dynamics simulations to investigate the effect of the Si3N4 membrane on water molecules inside CNTs. The internal electric field generated in the CNTs by the point charges of the Si3N4 membrane changes the structure and dynamical properties of water in the nanotubes, causing it to attain a disordered structure. The Si3N4 membrane decreases the diffusivity of water in the CNTs; this is because the Coulomb potential energy (i.e., electrostatic interaction) of water decreases owing to the presence of Si3N4, whereas the Lennard-Jones potential energy (i.e., van der Waals interaction) does not change significantly. Furthermore, electrostatic interactions make the water structure more stable in the CNTs. As a result, the Si3N4 membrane enhances the separation effect of the water-methanol mixture with CNTs in the presence of an external electric field. Furthermore, the threshold of the external electric field strength to induce water-methanol separation with CNTs is reduced owing to the presence of a silicon nitride membrane.
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Affiliation(s)
- Winarto
- Department of Mechanical Engineering, Faculty of Engineering, Brawijaya University, Jl. MT Haryono 167, Malang 65145, Indonesia
| | - Eiji Yamamoto
- Department of System Design Engineering, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Kenji Yasuoka
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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2
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Separation of binary organic mixture in T-shaped carbon nanotube separator: Insights from molecular dynamics simulation. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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3
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Winarto, Yamamoto E, Yasuoka K. Separation of water-alcohol mixtures using carbon nanotubes under an electric field. Phys Chem Chem Phys 2019; 21:15431-15438. [PMID: 31282508 DOI: 10.1039/c9cp01799b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon nanotubes (CNTs) are a promising candidate for separation membranes because of their ability to transport substances at very high flow rates. However, there is a tradeoff between achieving a high selectivity using small pore sizes and the reduction of water flux. Here, using molecular dynamics simulations, we report that CNTs can effectively separate water-methanol mixtures under an electric field. Without an electric field and under piston pressure, both water and methanol flow through a CNT, resulting in no separation effect. In contrast, under an electric field and high piston pressure, CNTs allow selective water permeation while rejecting the permeation of methanol molecules. This separation effect is caused by the ordered structures of water molecules in the CNT. A high filtering effect is observed under the conditions of high methanol concentration in the solution or even with large-diameter CNTs up to 3.39 nm. As long as the ordered structure of water in the CNTs can be maintained, the strong filtering effect can be maintained.
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Affiliation(s)
- Winarto
- Department of Mechanical Engineering, Faculty of Engineering, Brawijaya University, Jl. MT Haryono 167, Malang 65145, Indonesia
| | - Eiji Yamamoto
- Department of System Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Kenji Yasuoka
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
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Winarto, Takaiwa D, Yamamoto E, Yasuoka K. Separation of water-ethanol solutions with carbon nanotubes and electric fields. Phys Chem Chem Phys 2018; 18:33310-33319. [PMID: 27897278 DOI: 10.1039/c6cp06731j] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bioethanol has been used as an alternative energy source for transportation vehicles to reduce the use of fossil fuels. The separation of water-ethanol solutions from fermentation processes is still an important issue in the production of anhydrous ethanol. Using molecular dynamics simulations, we investigate the effect of axial electric fields on the separation of water-ethanol solutions with carbon nanotubes (CNTs). In the absence of an electric field, CNT-ethanol van der Waals interactions allow ethanol to fill the CNTs in preference to water, i.e., a separation effect for ethanol. However, as the CNT diameter increases, this ethanol separation effect significantly decreases owing to a decrease in the strength of the van der Waals interactions. In contrast, under an electric field, the energy of the electrostatic interactions within the water molecule structure induces water molecules to fill the CNTs in preference to ethanol, i.e., a separation effect for water. More importantly, the electrostatic interactions are dependent on the water molecule structure in the CNT instead of the CNT diameter. As a result, the separation effect observed under an electric field does not diminish over a wide CNT diameter range. Moreover, CNTs and electric fields can be used to separate methanol-ethanol solutions too. Under an electric field, methanol preferentially fills CNTs over ethanol in a wide CNT diameter range.
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Affiliation(s)
- Winarto
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. and Department of Mechanical Engineering, Faculty of Engineering, Brawijaya University, Jl. MT Haryono 167, Malang 65145, Indonesia
| | - Daisuke Takaiwa
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
| | - Eiji Yamamoto
- Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Kenji Yasuoka
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
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5
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Water Molecules in a Carbon Nanotube under an Applied Electric Field at Various Temperatures and Pressures. WATER 2017. [DOI: 10.3390/w9070473] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Wang H, Shi J, Liu G, Zhang Y, Zhang J, Li S. Investigation of Transport Properties of Water-Methanol Solution through a CNT with Oscillating Electric Field. J Phys Chem B 2017; 121:1041-1053. [PMID: 28068091 DOI: 10.1021/acs.jpcb.6b06509] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular dynamics simulations were used to investigate the transport properties of water-methanol solution getting through a carbon nanotube (CNT) with an oscillating electric field. Eight alternating electric fields with different oscillation periods were used in this work. Under the oscillating electric field, water molecules have the advantage of occupying a CNT over methanol molecules. Meanwhile, the space occupancy of water-methanol solution in the CNT increases as the oscillating period increases. More importantly, we found that the oscillating period of electric field affects the van der Waals interaction of the solution inside the CNT and the shell of the CNT, which results in the change in the number of hydrogen bonds in the water-methanol solution confined in the CNT. And the change in the hydrogen-bond network leads to the change in transport properties of water-methanol solution.
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Affiliation(s)
- Honglei Wang
- College of Environmental and Chemical Engineering, Dalian University , Dalian 116622, China
| | - Jin Shi
- Department of Environmental Science & Engineering, Fudan University , Shanghai 200433, China
| | - Guokui Liu
- Key laboratory of Colloid and Interface Chemistry, Shandong University , Jinan 250100, China
| | - Yongqin Zhang
- College of Environmental and Chemical Engineering, Dalian University , Dalian 116622, China
| | - Jingjing Zhang
- College of Environmental and Chemical Engineering, Dalian University , Dalian 116622, China
| | - Shenmin Li
- College of Environmental and Chemical Engineering, Dalian University , Dalian 116622, China
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7
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cif2tube – Algorithm for constructing nanotube and nanoscroll models from crystallographic information files. J Taiwan Inst Chem Eng 2016. [DOI: 10.1016/j.jtice.2016.08.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ma X, Agarwal S. Adsorption of Emerging Ionizable Contaminants on Carbon Nanotubes: Advancements and Challenges. Molecules 2016; 21:E628. [PMID: 27187338 PMCID: PMC6273103 DOI: 10.3390/molecules21050628] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/28/2016] [Accepted: 05/09/2016] [Indexed: 11/25/2022] Open
Abstract
The superior adsorption capacity of carbon nanotubes has been well recognized and there is a wealth of information in the literature concerning the adsorption of unionized organic pollutants on carbon nanotubes. Recently, the adsorption of emerging environmental pollutants, most of which are ionizable, has attracted increasing attention due to the heightened concerns about the accumulation of these emerging contaminants in the environment. These recent studies suggest that the adsorption of emerging ionizable contaminants on carbon nanotubes exhibit different characteristics than unionized ones. For example, a new charge-assisted intermolecular force has been proposed for ionizable compounds because some adsorption phenomenon cannot be easily explained by the conventional force theory. The adsorption of ionizable compounds also displayed much stronger dependence on solution pH and ionic strength than unionized compounds. This article aims to present a brief review on the current understanding of the adsorption of emerging ionizable contaminants to carbon nanotubes and discuss further research needs required to advance the mechanistic understanding of the interactions between ionizable contaminants and carbon nanotubes.
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Affiliation(s)
- Xingmao Ma
- Zachry Department of Civil Engineering, Texas A & M University, College Station, TX 77843, USA.
| | - Sarang Agarwal
- Zachry Department of Civil Engineering, Texas A & M University, College Station, TX 77843, USA.
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9
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Wesołowski RP, Terzyk AP. Dynamics of effusive and diffusive gas separation on pillared graphene. Phys Chem Chem Phys 2016; 18:17018-23. [DOI: 10.1039/c6cp02392d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this study we examine the ability of pillared graphene membranes to separate the species of two gas mixtures that are important from an industrial point of view: air and coal gas.
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Affiliation(s)
- Radosław P. Wesołowski
- Faculty of Chemistry
- Physicochemistry of Carbon Materials Research Group
- Nicolaus Copernicus University in Toruń
- 87-100 Toruń
- Poland
| | - Artur P. Terzyk
- Faculty of Chemistry
- Physicochemistry of Carbon Materials Research Group
- Nicolaus Copernicus University in Toruń
- 87-100 Toruń
- Poland
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Takaiwa D, Yamamoto E, Yasuoka K. Water–methanol separation with carbon nanotubes and electric fields. NANOSCALE 2015; 7:12659-12665. [PMID: 26397004 DOI: 10.1039/c5nr02182k] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Methanol is used in various applications, such as fuel for transportation vehicles, fuel cells, and in chemical industrial processes. Conventionally, separation of methanol from aqueous solution is by distillation. However, this method consumes a large amount of energy; hence development of a new method is needed. In this work, molecular dynamics simulations are performed to investigate the effect of an electric field on water–methanol separation by carbon nanotubes (CNTs) with diameters of 0.81 to 4.07 nm. Without an electric field, methanol molecules fill the CNTs in preference to water molecules. The preference of methanol to occupy the CNTs over water results in a separation effect. This separation effect is strong for small CNT diameters and significantly decreases with increasing diameter. In contrast, under an electric field, water molecules strongly prefer to occupy the CNTs over methanol molecules, resulting in a separation effect for water. More interestingly, the separation effect for water does not decrease with increasing CNT diameter. Formation of water structures in CNTs induced by an electric field has an important role in the separation of water from methanol.
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11
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Li R, Fan J, Li H, Yan X, Yu Y. Exploring the Dynamic Behaviors and Transport Properties of Gas Molecules in a Transmembrane Cyclic Peptide Nanotube. J Phys Chem B 2013; 117:14916-27. [DOI: 10.1021/jp408769u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rui Li
- College of Chemistry, Chemical Engineering
and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Jianfen Fan
- College of Chemistry, Chemical Engineering
and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Hui Li
- College of Chemistry, Chemical Engineering
and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Xiliang Yan
- College of Chemistry, Chemical Engineering
and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Yi Yu
- College of Chemistry, Chemical Engineering
and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
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12
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Kowalczyk P, He J, Hu M, Gauden PA, Furmaniak S, Terzyk AP. To the pore and through the pore: thermodynamics and kinetics of helium in exotic cubic carbon polymorphs. Phys Chem Chem Phys 2013; 15:17366-73. [PMID: 24022382 DOI: 10.1039/c3cp52708e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Applying pore size analysis, Monte Carlo simulations, and transition state theory, we study the molecular sieving properties of recently discovered crystalline exotic cubic carbon allotropes (Hu et al., J. Phys. Chem. C, 2012, 116, 24233-24238) at 298 K and infinite dilution. The fcc-C10 cubic carbon crystal shows unusual molecular sieving characteristics. The carbon cavities of the fcc-C10 cubic carbon polymorph (with an effective size of ~3.5-4 Å) are kinetically closed to common gaseous contaminants of He fluid (including: Ne, Ar, H2, and CO). Because the sizes of nanowindows connecting carbon cavities are comparable with the effective size of a He atom (~2.556 Å), we predict a significant resistance to self-diffusion of the He in the fcc-C10 crystal. Computed self-diffusion coefficients ~1.3 × 10(-6)-1.3 × 10(-7) cm(2) s(-1) for He inside fcc-C10 fall in the range characteristic of molecular diffusion in zeolites. Infrequent "jumps" of He atoms between neighboring carbon cavities and kinetic rejection of other gaseous particles indicate potential application of the fcc-C10 carbon polymorph for kinetic molecular sieving of He near ambient temperatures. The theoretical results presented here are useful for correct interpretation of the pore volumes of carbon molecular sieves measured from helium porosimetry.
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Affiliation(s)
- Piotr Kowalczyk
- Nanochemistry Research Institute, Department of Chemistry, Curtin University of Technology, P.O. Box U1987, Perth, 6845 Western Australia, Australia.
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13
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14
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Gauden PA, Terzyk AP, Furmaniak S, Wiśniewski M, Kowalczyk P, Bielicka A, Zieliński W. Porosity of closed carbon nanotubes compressed using hydraulic pressure. ADSORPTION 2013. [DOI: 10.1007/s10450-013-9518-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Surapathi A, Chen HY, Marand E, Karl Johnson J, Sedlakova Z. Gas sorption properties of zwitterion-functionalized carbon nanotubes. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2012.11.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Abstract
Research on mixed matrix membranes in which nanoparticles are used to enhance the membrane's performance in terms of flux, separation, and fouling resistance has boomed in the last years. This review probes on the specific features and benefits of one specific type of nanoparticles with a well-defined cylindrical structure, known as nanotubes. Nanotube structures for potential use in membranes are reviewed. These comprise mainly single-wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs), but also other structures and materials, which are less studied for membrane applications, can be used. Important issues related to polymer-nanotube interactions such as dispersion and alignment are outlined, and a categorization is made of the resultant membranes. Applications are reviewed in four different areas, that is, gas separation, water filtration, drug delivery, and fuel cells.
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Affiliation(s)
- Bart Van der Bruggen
- Laboratory for Applied Physical Chemistry and Environmental Technology, Department of Chemical Engineering, KU Leuven, W. de Croylaan 46, 3001 Leuven, Belgium
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17
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Torrie GM, Lakatos G, Patey GN. Structure and adsorption of water in nonuniform cylindrical nanopores. J Chem Phys 2010; 133:224703. [DOI: 10.1063/1.3505453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Single-walled carbon nanotubes as stationary phase in gas chromatographic separation and determination of argon, carbon dioxide and hydrogen. Anal Chim Acta 2010; 675:207-12. [DOI: 10.1016/j.aca.2010.07.019] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Revised: 07/12/2010] [Accepted: 07/12/2010] [Indexed: 11/20/2022]
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19
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Simple model of adsorption on external surface of carbon nanotubes—a new analytical approach basing on molecular simulation data. ADSORPTION 2010. [DOI: 10.1007/s10450-010-9223-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Du AJ, Sun CH, Zhu ZH, Lu GQ, Rudolph V, Smith SC. The effect of Fe doping on adsorption of CO2/N2 within carbon nanotubes: a density functional theory study with dispersion corrections. NANOTECHNOLOGY 2009; 20:375701. [PMID: 19706942 DOI: 10.1088/0957-4484/20/37/375701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An ab initio density functional theory (DFT) study with correction for dispersive interactions was performed to study the adsorption of N(2) and CO(2) inside an (8, 8) single-walled carbon nanotube. We find that the approach of combining DFT and van der Waals correction is very effective for describing the long-range interaction between N(2)/CO(2) and the carbon nanotube (CNT). Surprisingly, exohedral doping of an Fe atom onto the CNT surface will only affect the adsorption energy of the quadrupolar CO(2) molecule inside the CNT (20-30%), and not that of molecular N(2). Our results suggest the feasibility of enhancement of CO(2)/N(2) separation in CNT-based membranes by using exohedral doping of metal atoms.
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Affiliation(s)
- A J Du
- Centre for Computational Molecular Science, The University of Queensland, Australian Institute for Bioengineering and Nanotechnology Building 75, QLD 4072, Brisbane, Australia.
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21
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Liu L, Chen X. Nanofluidic Transport in Branching Nanochannels: A Molecular Sieve Based on Y-Junction Nanotubes. J Phys Chem B 2009; 113:6468-72. [DOI: 10.1021/jp900721h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ling Liu
- Columbia Nanomechanics Research Center, School of Engineering and Applied Sciences, Mail Code 4709, Columbia University, New York, New York 10027-6699
| | - Xi Chen
- Columbia Nanomechanics Research Center, School of Engineering and Applied Sciences, Mail Code 4709, Columbia University, New York, New York 10027-6699
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Kim YH, Yoon DK, Choi MC, Jeong HS, Kim MW, Lavrentovich OD, Jung HT. Confined self-assembly of toric focal conic domains (the effects of confined geometry on the feature size of toric focal conic domains). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:1685-1691. [PMID: 19133728 DOI: 10.1021/la802870z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A smectic liquid crystal (LC) containing a rigid biphenyl group and semifluorinated chains exhibits a high density of toric focal conic domains (TFCDs) arranged in an ordered array when confined within a microchannel. The formation of the TFCDs is strongly influenced by the width (W) and depth (h) of the confined microchannels, most importantly, by the channel depth. We studied a broad variety of microchannels, with varying width in the range of 3-200 mum and depth in the range of 2-10 mum. The radius of the TFCDs increases with increases in the width until the saturated radius is achieved, which is determined by the depth of the channel. We used the elastic-anchoring model of TFCD formation to explain the experimental observations. The model allows one to trace the dependence of the TFCD radius on the channel depth h, to explain why the TFCDs do not form in channels that are too shallow or too narrow.
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Affiliation(s)
- Yun Ho Kim
- Department of Chemical and Biomolecular Engineering (BK-21), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
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23
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Rawat DS, Krungleviciute V, Heroux L, Bulut M, Calbi MM, Migone AD. Dependence of single-walled carbon nanotube adsorption kinetics on temperature and binding energy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13465-13469. [PMID: 18954094 DOI: 10.1021/la8022002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present results for the isothermal adsorption kinetics of methane, hydrogen, and tetrafluoromethane on closed-ended single-walled carbon nanotubes. In these experiments, we monitor the pressure decrease as a function of time as equilibrium is approached, after a dose of gas is added to the cell containing the nanotubes. The measurements were performed at different fractional coverages limited to the first layer. The results indicate that, for a given coverage and temperature, the equilibration time is an increasing function of E/(k(B)T), where E is the binding energy of the adsorbate and k(B)T is the thermal energy. These findings are consistent with recent theoretical predictions and computer simulations results that we use to interpret the experimental measurements.
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Affiliation(s)
- D S Rawat
- Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, USA
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Mauter MS, Elimelech M. Environmental applications of carbon-based nanomaterials. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:5843-59. [PMID: 18767635 DOI: 10.1021/es8006904] [Citation(s) in RCA: 655] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The unique and tunable properties of carbon-based nanomaterials enable new technologies for identifying and addressing environmental challenges. This review critically assesses the contributions of carbon-based nanomaterials to a broad range of environmental applications: sorbents, high-flux membranes, depth filters, antimicrobial agents, environmental sensors, renewable energy technologies, and pollution prevention strategies. In linking technological advance back to the physical, chemical, and electronic properties of carbonaceous nanomaterials, this article also outlines future opportunities for nanomaterial application in environmental systems.
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Affiliation(s)
- Meagan S Mauter
- Department of Chemical Engineering, Environmental Engineering Program, Yale University, P.O. Box 208286, New Haven, Connecticut 06520-8286, USA
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Babarao R, Jiang J. Diffusion and separation of CO2 and CH4 in silicalite, C168 schwarzite, and IRMOF-1: a comparative study from molecular dynamics simulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:5474-5484. [PMID: 18433152 DOI: 10.1021/la703434s] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Recently we have investigated the storage and adsorption selectivity of CO(2) and CH(4) in three different classes of nanoporous materialssilicalite, IRMOF-1, and C(168) schwarzite through Monte Carlo simulation (Babarao, R.; Hu, Z.; Jiang, J. Langmuir, 2007, 23, 659). In this work, the self-, corrected, and transport diffusivities of CO(2) and CH(4) in these materials are examined using molecular dynamics simulation. The activation energies at infinite dilution are evaluated from the Arrhenius fits to the diffusivities at various temperatures. As loading increases, the self-diffusivities in the three frameworks decrease as a result of the steric hindrance; the corrected diffusivities remain nearly constant or decrease approximately linearly depending on the adsorbate and framework; and the transport diffusivities generally increase except for CO(2) in IRMOF-1. The correlation effects are identified to reduce from MFI, C(168) to IRMOF-1, in accordance with the porosity increasing in the three frameworks. Predictions of self-, corrected, and transport diffusivities for pure CO(2) and CH(4) from the Maxwell-Stefan formulation match the simulation results well. In a CO(2)/CH(4) mixture, the self-diffusivities decreases with loading, and good agreement is found between simulated and predicted results. On the basis of the adsorption and self-diffusivity in the mixture, the permselectivity is found to be marginal in IRMOF-1, slightly enhanced in MFI, and greatest in C(168) schwarzite. Although IRMOF-1 has the largest storage capacity for CH(4) and CO(2), its selectivity is not satisfactory.
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Affiliation(s)
- Ravichandar Babarao
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Singapore 117576
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26
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Avila AM. Modeling the Transient Adsorption Process of Ternary Mixtures on Nanoporous Zeolitic Adsorbents in Batch Systems. SEP SCI TECHNOL 2008. [DOI: 10.1080/01496390701870648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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27
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Affiliation(s)
- Kwang-Hua W. Chu
- School of Physics and Information Engineering, Hebei Normal University, Shijiazhuang 050016, People's Republic of China, and P.O. Box 39, Tou-Di-Ban, Road Xihong, Urumqi 830000, People's Republic of China
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