calque

Workshops

Interactions and Transport of Charged Species in Bulk and at Interfaces

July 4, 2016 to July 7, 2016
Location : CECAM-AT

Colloidal particles at liquid interfaces: self-assembly due to capillary, magnetic and electrokinetic interactions

Jens Harting
[1] Forschungszentrum Jülich GmbH, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Fürther Str. 248, 90429 Nürnberg, Germany [2] Department of Applied Physics, Eindhoven University of Technology, Postbus 513, 5600MB Eindhoven, The Netherlands

Abstract

Colloidal particles are known to be very efficient stabilizers for fluid interfaces with applications in the food and cosmetics industry, enhanced oil recovery, drug delivery or waste water management. Capillary interactions between particles with different shape, contact angle on the particle surface, or particle-particle interactions are also promising candidates to self-assemble complex structures for the production of new soft materials or applications in the printing and coating industries. We present computer simulations based on a hybrid lattice Boltzmann and molecular dynamics method [1,2] and demonstrate the impact of the particle shape and contact angle on the formation, rheology and stability of particle stabilized emulsions such as Pickering emulsions and bijels [3,4]. We then demonstrate new ways to self-assemble complex structures by means of capillary interactions and external magnetic fields to steer the movement of ellipsoidal particles [5,6,7] or magnetic Janus particles with a hydrophobic and a hydrophilic side [8]. At last, we present simulations of charged colloids immersed in binary electrolyte solutions based on a new combination of the Shan-Chen multicomponent lattice Boltzmann method and the link-flux method to resolve the ions’ kinetics [9,10].



References

[1] F. Jansen, J. Harting, “From Bijels to Pickering emulsions: a lattice Boltzmann study”, Physical Review E 83, 046707 (2011)
[2] S. Frijters, F. Günther, J. Harting, “Effects of nanoparticles and surfactant on droplets in shear flow”, Soft Matter 8, 6542 (2012)
[3] F. Günther, S. Frijters, J. Harting, “Timescales of emulsion formation caused by anisotropic particles”, Soft Matter 10, 4977 (2014)
[4] S. Frijters, F. Günther, J. Harting, “Domain and droplet sizes in emulsions stabilized by colloidal particles”, Physical Review E 90, 042307 (2014)
[5] G. B. Davies, T. Krüger, P. V. Coveney, J. Harting, “Detachment energies of spheroidal particles from fluid-fluid interfaces”, Journal of Chemical Physics 141, 154902 (2014)
[6] G. B. Davies, T. Krüger, P. V. Coveney, J. Harting, F. Bresme, “Interface deformations affect the orientation transition of magnetic ellipsoidal particles adsorbed at fluid-fluid interfaces”, Soft Matter 10, 6742 (2014)
[7] G. B. Davies, T. Krüger, P. V. Coveney, J. Harting, F. Bresme, “Assembling ellipsoidal particles at fluid interfaces using switchable dipolar capillary interactions”, Advanced Materials 26, 6715 (2014)
[8] Q. Xie, G. B. Davies, F. Günther, J. Harting, “Tunable dipolar capillary deformations for magnetic Janus particles at fluid-fluid interfaces”, Soft Matter 11, 3581 (2015)
[9] F. Capuani, I. Pagonabarraga, D. Frenkel, “Discrete solution of the electrokinetic equations”, Journal of Chemical Physics 121, 973 (2004)
[10] N. Rivas, S. Frijters, J. Harting, preprint (2016)