scholarly journals A Water/Ion Separation Device: Theoretical and Numerical Investigation

2021 ◽  
Vol 11 (18) ◽  
pp. 8548
Author(s):  
Filippos Sofos
Keyword(s):  
Electric Field ◽  
Volumetric Flow Rate ◽  
External Pressure ◽  
Theoretical Background ◽  
System Component ◽  
High Concentration ◽  
Ion Separation ◽  
Wide Range ◽  
Dynamics Simulations ◽  
Separation Cell

An array of ion separation cells is presented in this work, to propose a novel desalination device. Molecular Dynamics simulations have been incorporated to establish the theoretical background and calculate all parameters that could lead the manufacturing step. The main system component is an ion separation cell, in which water/NaCl solution flows due to an external pressure difference and ions are directed towards the non-permeable walls under the effect of an electric field, with direction perpendicular to the flow. Clean water is gathered from the output, while the remaining, high-concentration water/ion solution is re-cycled in the cells. The strength of the electric field, cell dimensions, and wall/fluid interactions are investigated over a wide range, and shear viscosity and the volumetric flow rate are calculated for each case.

Structures of Water Molecules in Carbon Nanotubes Induced with Electric Fields and its Application for Water-Methanol Separation

2016 ◽  
Vol 842 ◽  
pp. 453-456 ◽  
Author(s):  
Winarto ◽  
Daisuke Takaiwa ◽  
Eiji Yamamoto ◽  
Kenji Yasuoka
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Electrostatic Interaction ◽  
Water Molecules ◽  
Ordered Structures ◽  
Separation Effect ◽  
Wide Range ◽  
Dynamics Simulations

Water confined in carbon nanotubes (CNTs) under the influence of an electric field has interesting properties that are potential for nanofluidic-based applications. With molecular dynamics simulations, this work shows that the electric field induces formation of ordered structures of water molecules in the CNTs. Formation of the ordered structures strengthens the electrostatic interaction between the water molecules. As a result, water strongly prefers to fill CNTs over methanol and it produces a separation effect. Interestingly, the separation effect with the electric field does not decrease for a wide range of CNT diameter.

scholarly journals Molecular Dynamics Simulations of Ion Drift in Nanochannel Water Flow

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2373
Author(s):  
Filippos Sofos ◽  
Theodoros Karakasidis ◽  
Ioannis E. Sarris
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Membrane Fouling ◽  
Volumetric Flow Rate ◽  
Small Scale ◽  
Channel Height ◽  
Electric Field Magnitude ◽  
Field Magnitude ◽  
Ion Drift ◽  
Ion Separation

The present paper employs Molecular Dynamics (MD) simulations to reveal nanoscale ion separation from water/ion flows under an external electric field in Poiseuille-like nanochannels. Ions are drifted to the sidewalls due to the effect of wall-normal applied electric fields while flowing inside the channel. Fresh water is obtained from the channel centerline, while ions are rejected near the walls, similar to the Capacitive DeIonization (CDI) principles. Parameters affecting the separation process, i.e., simulation duration, percentage of the removal, volumetric flow rate, and the length of the nanochannel incorporated, are affected by the electric field magnitude, ion correlations, and channel height. For the range of channels investigated here, an ion removal percentage near 100% is achieved in most cases in less than 20 ns for an electric field magnitude of E = 2.0 V/Å. In the nutshell, the ion drift is found satisfactory in the proposed nanoscale method, and it is exploited in a practical, small-scale system. Theoretical investigation from this work can be projected for systems at larger scales to perform fundamental yet elusive studies on water/ion separation issues at the nanoscale and, one step further, for designing real devices as well. The advantages over existing methods refer to the ease of implementation, low cost, and energy consumption, without the need to confront membrane fouling problems and complex electrode material fabrication employed in CDI.

Tuning the Electric Field Response of MOFs by Rotatable Dipolar Linkers

2019 ◽  
Author(s):  
Johannes P. Dürholt ◽  
Babak Farhadi Jahromi ◽  
Rochus Schmid
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Structural Changes ◽  
Dielectric Behavior ◽  
Two Dimensions ◽  
Dielectric Constants ◽  
Electric Response ◽  
Dipole Strength ◽  
Metal Organic ◽  
Dynamics Simulations

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.

General Trend of Negative Transference Number in Li Salt/Ionic Liquid Mixtures

2019 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Ionic Liquid ◽  
Transference Number ◽  
Liquid Mixtures ◽  
Single Linkage ◽  
Self Diffusion ◽  
Wide Range ◽  
Single Linkage Cluster ◽  
Concentrated Solution ◽  
The One ◽  
Dynamics Simulations

We show that strong cation-anion interactions in a wide range of lithium-salt/ionic liquid mixtures result in a negative lithium transference number, using molecular dynamics simulations and rigorous concentrated solution theory. This behavior fundamentally deviates from the one obtained using self-diffusion coefficient analysis and agrees well with experimental electrophoretic NMR measurements, which accounts for ion correlations. We extend these findings to several ionic liquid compositions. We investigate the degree of spatial ionic coordination employing single-linkage cluster analysis, unveiling asymmetrical anion-cation clusters. Additionally, we formulate a way to compute the effective lithium charge that corresponds to and agrees well with electrophoretic measurements and show that lithium effectively carries a negative charge in a remarkably wide range of chemistries and concentrations. The generality of our observation has significant implications for the energy storage community, emphasizing the need to reconsider the potential of these systems as next generation battery electrolytes.<br>

Development of PEF extraction technology by Maguin

2015 ◽  
pp. 758-760
Author(s):  
Romain Delecourt ◽  
Loïc Marsal
Keyword(s):  
Sugar Beet ◽  
Electric Field ◽  
Pulsed Electric Field ◽  
Extraction Technology ◽  
Application System ◽  
Wide Range ◽  
Type Machine

Maguin (France) is still active in the application of pulsed electric field (PEF) technology. After having carried out successful tests on a 10 t/h pilot screw-type machine on sugar beet cossettes, a new application system based on a roller technology has been developed. This technology allows a wide range of application due to its flexibility with flowrates and materials. A variety of process schemes are proposed to ensure the best performance of the PEF technology.

scholarly journals Polymer cyclization for the emergence of hierarchical nanostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chaojian Chen ◽  
Manjesh Kumar Singh ◽  
Katrin Wunderlich ◽  
Sean Harvey ◽  
Colette J. Whitfield ◽  
...  
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Hierarchical Structures ◽  
Structural Similarity ◽  
Vital Role ◽  
Nanomaterial Synthesis ◽  
Wide Range ◽  
Linear Poly ◽  
Polymer Folding ◽  
Dynamics Simulations

AbstractThe creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. Inspired by the programmability and precise three-dimensional architectures of biomolecules, here we demonstrate the strategy of fabricating controlled hierarchical structures through self-assembly of folded synthetic polymers. Linear poly(2-hydroxyethyl methacrylate) of different lengths are folded into cyclic polymers and their self-assembly into hierarchical structures is elucidated by various experimental techniques and molecular dynamics simulations. Based on their structural similarity, macrocyclic brush polymers with amphiphilic block side chains are synthesized, which can self-assemble into wormlike and higher-ordered structures. Our work points out the vital role of polymer folding in macromolecular self-assembly and establishes a versatile approach for constructing biomimetic hierarchical assemblies.

The vibration of electrified water drops

1971 ◽  
Vol 322 (1551) ◽  
pp. 523-534 ◽  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Axial Ratio ◽  
Uniform Electric Field ◽  
Interferometric Technique ◽  
Photographic Analysis ◽  
Wide Range ◽  
Water Drops ◽  
Strength And Deformation ◽  
A Charge

Pressure has been used as the principal parameter in calculations of the fundamental vibrational frequencies of spherical drops of radius R , density ρ, and surface tension T carrying a charge Q or uncharged spheroidal drops of axial ratio a / b situated in a uniform electric field of strength E . Freely vibrating charged drops have a frequency f = f 0 ( 1 - Q 2 /16π R 3 T ) ½ , as shown previously by Rayleigh (1882) using energy considerations; f 0 is the vibrational frequency of non-electrified drops (Rayleigh 1879). The fundamental frequency of an uncharged drop in an electric field will decrease with increasing field strength and deformation a / b and will equal zero when E ( R )/ T ) ½ = 1.625 and a / b = 1.86; these critical values correspond to the disintegration conditions derived by Taylor (1964). An interferometric technique involving a laser confirmed the accuracy of the calculations concerned with charged drops. The vibration of water drops of radius around 2 mm was studied over a wide range of temperatures as they fell through electric fields either by suspending them in a vertical wind tunnel or allowing them to fall between a pair of vertical electrodes. Photographic analysis of the vibrations revealed good agreement between theory and experiment over the entire range of conditions studied even though the larger drops were not accurately spheroidal and the amplitude of the vibrations was large.

Sign in / Sign up

Export Citation Format

Share Document