Electrophoresis of Janus particles: A molecular dynamics simulation study.

In this work, we use molecular dynamics and lattice-Boltzmann simulations to study the properties of charged Janus particles in an electric field. We show that for a relatively small net charge and a thick electrostatic diffuse layer, mobilities of Janus particles and uniformly charged colloids of the same net charge are identical. However, for higher charges and thinner diffuse layers, the Janus particles always show lower electrophoretic mobility. We also demonstrate that the Janus particles align with the electric field and the angular deviation from the field's direction is related to their dipole moment. We show that the latter is affected by the thickness of electrostatic diffuse layer and strongly correlates with the electrophoretic mobility.

[1]  Lee R. White,et al.  Electrophoretic mobility of a spherical colloidal particle , 1978 .

[2]  W. Marsden.  I and J , 2012 .

[3]  Aleksey V Belyaev,et al.  Electro-osmosis on anisotropic superhydrophobic surfaces. , 2011, Physical review letters.

[4]  John L. Anderson,et al.  Effect of nonuniform zeta potential on particle movement in electric fields , 1985 .

[5]  J. J. López-García,et al.  Electrical double layer around a spherical colloid particle: the excluded volume effect. , 2007, Journal of colloid and interface science.

[6]  Axel Arnold,et al.  ESPResSo 3.1: Molecular Dynamics Software for Coarse-Grained Models , 2013 .

[7]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[8]  Joshua M. Dempster,et al.  Aggregation of Heterogeneously Charged Colloids. , 2016, ACS nano.

[9]  Christian Holm,et al.  The Raspberry model for hydrodynamic interactions revisited. II. The effect of confinement. , 2015, The Journal of chemical physics.

[10]  S. Griffis.  EDITOR , 1997, Journal of Navigation.

[11]  Armand Ajdari,et al.  Transverse electrokinetic and microfluidic effects in micropatterned channels: lubrication analysis for slab geometries. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[12]  L. Yeh,et al.  Electrophoresis of a particle at an arbitrary surface potential and double layer thickness: importance of nonuniformly charged conditions. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[13]  H. Orland,et al.  Adsorption of large ions from an electrolyte solution: a modified Poisson–Boltzmann equation , 1999 .

[14]  Jiaye Su,et al.  Solubility and transport of cationic and anionic patterned nanoparticles. , 2012, Physical review. E, Statistical, nonlinear, and soft matter physics.

[15]  A. V. Belyaev,et al.  Electrohydrodynamics near hydrophobic surfaces. , 2014, Physical review letters.

[16]  Vladimir Lobaskin,et al.  A new model for simulating colloidal dynamics , 2004 .

[17]  Cai‐Feng Wang,et al.  Versatile Bifunctional Magnetic‐Fluorescent Responsive Janus Supraballs Towards the Flexible Bead Display , 2011, Advanced materials.

[18]  S. Anthony,et al.  Single-particle tracking of janus colloids in close proximity. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[19]  Hans-Jörg Limbach,et al.  ESPResSo - an extensible simulation package for research on soft matter systems , 2006, Comput. Phys. Commun..

[20]  P. Ahlrichs,et al.  Simulation of a single polymer chain in solution by combining lattice Boltzmann and molecular dynamics , 1999, cond-mat/9905183.

[21]  B. Duenweg,et al.  Colloidal electrophoresis: scaling analysis, Green–Kubo relation, and numerical results , 2008, 0808.2583.

[22]  Electrophoresis of colloidal dispersions in the low-salt regime. , 2006, Physical review letters.

[23]  Christian Holm,et al.  The raspberry model for hydrodynamic interactions revisited. I. Periodic arrays of spheres and dumbbells. , 2015, The Journal of chemical physics.

[24]  Ramin Golestanian,et al.  Self-motile colloidal particles: from directed propulsion to random walk. , 2007, Physical review letters.

[25]  E. M. Lifshitz,et al.  Course in Theoretical Physics , 2013 .

[26]  O. Lenz,et al.  The optimal P3M algorithm for computing electrostatic energies in periodic systems. , 2007, The Journal of chemical physics.

[27]  John L. Anderson,et al.  Colloid Transport by Interfacial Forces , 1989 .

[28]  Marian Smoluchowski,et al.  Contribution à la théorie de l'endosmose électrique et de quelques phénomènes corrélatifs , 1924 .

[29]  Christian Holm,et al.  Electrophoretic mobility of a charged colloidal particle: a computer simulation study , 2004 .

[30]  B. Dünweg,et al.  Numerical electrokinetics , 2012, Journal of physics. Condensed matter : an Institute of Physics journal.

[31]  Daniele Rocchi,et al.  Lecture notes in computational science and engineering , 2010 .

[32]  Andreas Walther,et al.  Janus particles: synthesis, self-assembly, physical properties, and applications. , 2013, Chemical reviews.

[33]  H. Ohshima,et al.  Electrophoretic mobility of a colloidal particle with constant surface charge density. , 2010, Langmuir.

[34]  M. Cates,et al.  Clustering and Pattern Formation in Chemorepulsive Active Colloids. , 2015, Physical review letters.