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Changes in Electrical Conductance of Polymer Composites Melts Due to Carbon Nanofiller Particles Migration. Polymers (Basel) 2021; 13:polym13071030. [PMID: 33810308 PMCID: PMC8036904 DOI: 10.3390/polym13071030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/11/2021] [Accepted: 03/24/2021] [Indexed: 01/29/2023] Open
Abstract
In this work, the results of investigation of the effect of polymer composite melts electrical conductance increase with time are presented. The conductance time dependencies were obtained for composites based on polypropylene filled with carbon nanoparticles of different types. The dependencies were analyzed to demonstrate the possibility of correlation of the conductance kinetics with different composite parameters, such as the filler geometry. Additional studies were carried out, such as electron microscopy study, conductance measurements after consecutive surface layer removal, and composite melt conductance measurements using a three-electrode scheme. The results showed that the increased electrical conductance of the composite materials can be attributed to the formation of an enriched with the filler particles surface layer, which happens during the stay of the composite in a melt state. Analysis of the experimental data, along with the results of numerical modeling, allowed to suggest a possible filler distribution transformation scheme. The physical premises behind the investigated effect are discussed.
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Asta AJ, Palaia I, Trizac E, Levesque M, Rotenberg B. Lattice Boltzmann electrokinetics simulation of nanocapacitors. J Chem Phys 2019; 151:114104. [DOI: 10.1063/1.5119341] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Adelchi J. Asta
- Sorbonne Universités, CNRS, Physico-Chimie des électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France
| | - Ivan Palaia
- LPTMS, UMR 8626, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Emmanuel Trizac
- LPTMS, UMR 8626, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Maximilien Levesque
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Benjamin Rotenberg
- Sorbonne Universités, CNRS, Physico-Chimie des électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, Amiens, France
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Asta A, Levesque M, Rotenberg B. Moment propagation method for the dynamics of charged adsorbing/desorbing species at solid-liquid interfaces. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1461944] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Adelchi Asta
- Sorbonne Université, CNRS, Physicochimie des électrolytes et nanosystèmes interfaciaux, UMR PHENIX , Paris, France
| | - Maximilien Levesque
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris, France
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physicochimie des électrolytes et nanosystèmes interfaciaux, UMR PHENIX , Paris, France
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Persson RAX, Voulgarakis NK, Chu JW. Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics. J Chem Phys 2014; 141:174105. [DOI: 10.1063/1.4900498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Rasmus A. X. Persson
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan
| | | | - Jhih-Wei Chu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan
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Keller F, Nirschl H, Dörfler W. Primary charge effects on prolate spheroids with moderate aspect ratios. J Colloid Interface Sci 2011; 363:690-702. [PMID: 21855888 DOI: 10.1016/j.jcis.2011.07.081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/29/2011] [Accepted: 07/25/2011] [Indexed: 10/17/2022]
Abstract
In this article, we investigate the behavior of charged spheroidal colloids with moderate aspect ratios in linear flow fields. We use direct numerical simulation with body-fitted grids for the solution of the Stokes-Poisson-Nernst-Planck system to include all non-linear effects. Therefore, we propose an efficient semi-implicit time discretization based on a splitting of the Stokes equation. We will study the effects of the electric double layer on the forces, torques and on the motion of spheroidal particles. For low Reynolds numbers, we find approximating linear expressions between the ambient fluid flow and the force and torque on the particle. The description of this linear behavior is based on the resistance functions, whose dependencies on the Debye length and the zeta potential are investigated. It is recovered that the resistance functions obey a quadratic dependence on the zeta potential in the small zeta potential regime. For low values of the zeta potential, approximate formulas for the resistance functions are given. The approximation properties are carefully studied by comparing the approximate results with direct numerical simulations. For the case of a shear flow, the approximate formulas can be used to avoid time-consuming direct numerical simulations.
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Affiliation(s)
- Florian Keller
- Institute of Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
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Giupponi G, Pagonabarraga I. Determination of the zeta potential for highly charged colloidal suspensions. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:2546-2554. [PMID: 21576170 DOI: 10.1098/rsta.2011.0024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We compute the electrostatic potential at the surface, or zeta potential ζ, of a charged particle embedded in a colloidal suspension using a hybrid mesoscopic model. We show that, for weakly perturbing electric fields, the value of ζ obtained at steady state during electrophoresis is statistically indistinguishable from ζ in thermodynamic equilibrium. We quantify the effect of counter-ion concentration on ζ. We also evaluate the relevance of the lattice resolution for the calculation of ζ and discuss how to identify the effective electrostatic radius.
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Affiliation(s)
- Giovanni Giupponi
- Departament de Fisica Fonamental, Universitat de Barcelona, Carrer Marti i Franques, 08028 Barcelona, Spain.
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8
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Shi Y, Yu Z, Shao X. Combination of the direct-forcing fictitious domain method and the sharp interface method for the three-dimensional dielectrophoresis of particles. POWDER TECHNOL 2011. [DOI: 10.1016/j.powtec.2011.02.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Porion P, Faugère AM, Michot LJ, Paineau E, Delville A. Orientational microdynamics and magnetic-field-induced ordering of clay platelets detected by 2H NMR spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:7035-7044. [PMID: 20047274 DOI: 10.1021/la904298d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The orientation of montmorillonite clays induced by a static magnetic field is quantified by using (2)H NMR spectroscopy. Indeed, the residual quadrupolar splitting of the (2)H resonance line measured for heavy water is a direct consequence of the specific orientation of the clay platelets in the static magnetic field. In the dilute regime, this residual splitting increases linearly with clay concentration, which confirms that the clay/clay electrostatic repulsions remain negligible by comparison with the diamagnetic coupling of these anisotropic platelets. At higher concentration, the electrostatic repulsion between clay particles markedly enhances the detected splitting. Such enhancement is well predicted by numerical simulations. By varying the size of the clay platelets and the strength of the static magnetic field, it is possible to evaluate the order of magnitude of the diamagnetic susceptibility of these anisotropic colloids.
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Affiliation(s)
- Patrice Porion
- Centre de Recherche sur la Matière Divisée, CNRS-Université d'Orléans, UMR6619, 45071 Orléans Cedex 02, France.
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He P, Mejia AF, Cheng Z, Sun D, Sue HJ, Dinair DS, Marquez M. Hindrance function for sedimentation and creaming of colloidal disks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:026310. [PMID: 20365654 DOI: 10.1103/physreve.81.026310] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2009] [Indexed: 05/29/2023]
Abstract
We report the first measurement of the hindrance function for sedimentation or creaming of disk-shaped colloids via the analytical centrifugation. Disks align with the external flow right above a volume fraction of a few percent, and this effect is extremely sensitive to the aspect ratio of disks. Due to this alignment effect, disk sedimentation or creaming demonstrates distinct trends in dilute and semidilute regions.
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Affiliation(s)
- Peng He
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, USA
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Pagonabarraga I, Rotenberg B, Frenkel D. Recent advances in the modelling and simulation of electrokinetic effects: bridging the gap between atomistic and macroscopic descriptions. Phys Chem Chem Phys 2010; 12:9566-80. [DOI: 10.1039/c004012f] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Nakayama Y, Kim K, Yamamoto R. Simulating (electro)hydrodynamic effects in colloidal dispersions: smoothed profile method. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2008; 26:361-368. [PMID: 19230114 DOI: 10.1140/epje/i2007-10332-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Previously, we have proposed a direct simulation scheme for colloidal dispersions in a Newtonian solvent (Phys. Rev. E 71, 036707 (2005)). An improved formulation called the "Smoothed Profile (SP) method" is presented here in which simultaneous time-marching is used for the host fluid and colloids. The SP method is a direct numerical simulation of particulate flows and provides a coupling scheme between the continuum fluid dynamics and rigid-body dynamics through utilization of a smoothed profile for the colloidal particles. Moreover, the improved formulation includes an extension to incorporate multicomponent fluids, allowing systems such as charged colloids in electrolyte solutions to be studied. The dynamics of the colloidal dispersions are solved with the same computational cost as required for solving non-particulate flows. Numerical results which assess the hydrodynamic interactions of colloidal dispersions are presented to validate the SP method. The SP method is not restricted to particular constitutive models of the host fluids and can hence be applied to colloidal dispersions in complex fluids.
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Affiliation(s)
- Y Nakayama
- Department of Chemical Engineering, Kyushu University, Fukuoka 819-0395, Japan.
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Rex M, Löwen H. Influence of hydrodynamic interactions on lane formation in oppositely charged driven colloids. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2008; 26:143-50. [PMID: 18324352 DOI: 10.1140/epje/i2007-10274-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 01/23/2008] [Indexed: 05/18/2023]
Abstract
The influence of hydrodynamic interactions on lane formation of oppositely charged driven colloidal suspensions is investigated using Brownian dynamics computer simulations performed on the Rotne-Prager level of the mobility tensor. Two cases are considered, namely sedimentation and electrophoresis. In the latter case the Oseen contribution to the mobility tensor is screened due to the opposite motion of counterions. The simulation results are compared to that resulting from simple Brownian dynamics where hydrodynamic interactions are neglected. For sedimentation, we find that hydrodynamic interactions strongly disfavor laning. In the steady state of lanes, a macroscopic phase separation of lanes is observed. This is in marked contrast to the simple Brownian case where a finite size of lanes was obtained in the steady state. For strong Coulomb interactions between the colloidal particles a lateral square lattice of oppositely driven lanes is stable similar to the simple Brownian dynamics. In an electric field, on the other hand, the behavior is found in qualitative and quantitative accordance with the case of neglected hydrodynamics.
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Affiliation(s)
- M Rex
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, Düsseldorf, Germany.
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Padding JT, Louis AA. Interplay between hydrodynamic and Brownian fluctuations in sedimenting colloidal suspensions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:011402. [PMID: 18351852 DOI: 10.1103/physreve.77.011402] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Indexed: 05/26/2023]
Abstract
We apply a hybrid molecular dynamics and mesoscopic simulation technique to study the steady-state sedimentation of hard sphere particles for Peclet number (Pe) ranging from 0.08 to 12. Hydrodynamic backflow causes a reduction of the average sedimentation velocity relative to the Stokes velocity. We find that this effect is independent of Pe number. Velocity fluctuations show the expected effects of thermal fluctuations at short correlation times. At longer times, nonequilibrium hydrodynamic fluctuations are visible, and their character appears to be independent of the thermal fluctuations. The hydrodynamic fluctuations dominate the diffusive behavior even for modest Pe number, while conversely the short-time fluctuations are dominated by thermal effects for surprisingly large Pe numbers. Inspired by recent experiments, we also study finite sedimentation in a horizontal planar slit. In our simulations distinct lateral patterns emerge, in agreement with observations in the experiments.
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Affiliation(s)
- J T Padding
- Computational Biophysics, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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Mukhija D, Solomon MJ. Translational and rotational dynamics of colloidal rods by direct visualization with confocal microscopy. J Colloid Interface Sci 2007; 314:98-106. [PMID: 17560590 DOI: 10.1016/j.jcis.2007.05.055] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 05/02/2007] [Accepted: 05/06/2007] [Indexed: 11/28/2022]
Abstract
We report an experimental method to characterize the dynamics of colloidal rods by measuring their rotation and translation in three dimensions with confocal microscopy. The method relies on solvent viscosification to retard dynamics to time scales that are compatible with 3D confocal optical microscopy. Because the method yields a full three-dimensional characterization of rod displacement and orientation, it is applicable to situations in which complex, anisotropic dynamics emerge. Examples include behavior in liquid crystal phases with both orientational and positional order, suspensions subjected to applied fields such as shear flow or sedimentation, and the emerging area of anisotropic particle dynamics. We demonstrate the performance of the method by quantifying the Brownian motion of fluorescent poly(methyl methacrylate) rods (aspect ratio, L/D=3.1 and 7.0) grafted with poly(dimethylsiloxane) stabilizer. The rods are dispersed at dilute concentration in a solvent mixture of viscosity 2.0 Pa s. Rod translational and rotational diffusivities are extracted from the measured translational mean square displacement of the centroid positions and of the rod unit vector u(t), respectively. Rod orientational dynamics are characterized relative to both their azimuthal and polar angles. Probability distributions for the translation and rotation in the frame of rod are computed from the measurements. Experimental values obtained agree well with theory available for the dynamics of isolated rods.
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Affiliation(s)
- Deshpremy Mukhija
- Department of Chemical Engineering, University of Michigan, 3410 G.G. Brown, 2300 Hayward St., Ann Arbor, MI 48109-2136, USA.
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Abstract
A numerical algorithm is presented for the standard model of macroion electrokinetics and certain generalizations of it. The macroion consists of a cylindrical section with identical, hemispheroidal endcaps, each piece having arbitrary length. The system of one macroion and adjoining salt solution is subjected to an arbitrary sequence of pulsed electrical fields and pulsed translational and rotational velocities. Numerical solutions are obtained for the time dependent electrostatic and mobile ion concentration fields and the solvent velocity. From these fields the dielectric response, force, and torque are calculated. Generalizations of the standard model include the diffusive motion of macroion surface charges, partial slip of solvent motion at the macroion surface, and a simple model for the reactive exchange of surface charge with solution ions. The primary illustrative application is to recent measurements of electric birefringence versus applied field frequency for poly-(tetrafluorothylene) colloidal particles, but a few results are presented for the dielectric response of DNA fragments and of spherical colloidal particles. The source code and additional details are provided as supplementary documentation.
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Affiliation(s)
- Marshall Fixman
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
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