Print Email Facebook Twitter Orientation of Spherical Janus Nanoparticles Title Orientation of Spherical Janus Nanoparticles: Force and Torque Calculations due to an External Electric Field Author van de Velde, Jeroen (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Applied Sciences; TU Delft ImPhys/Optics) Contributor Adam, A.J.L. (mentor) Dubbeldam, J.L.A. (mentor) Bouwman, W.G. (graduation committee) Urzúa-Torres, Carolina (graduation committee) Degree granting institution Delft University of Technology Programme Applied Mathematics | Applied Physics Date 2022-07-07 Abstract Janus particles are colloidal particles for which one half of the surface has different attributes than the other half. One property of a spherical dielectric particle with half of its surface covered by a layer of another dielectric or metal is that it has a non-uniform scattering pattern when exposed to light. However, the angle with which the light is shone on the particle has a large effect on the scattering pattern produced. Thus it is important that we are able to orient these Janus particles. The orientation can be controlled if we apply an electric field to the particle for example. The movement of colloidal particles with an electric field is widely studied and this field is called dielectrophoresis. For a Janus particle, the calculations for the force and torque become complicated. The movement and rotation of these particles have been studied, however, no analytic solution has been found. In this report, we derive a semi-analytic description of the force and torque due to an external electric field on a spherical Janus particle. For this, first the potential due to an external electric field is determined and then the force and torque are calculated with two methods: the dipole approximation and the Maxwell Stress Tensor method. In the dipole approximation, there is no force on the Janus particle. But, there is a torque on the particle in the dipole approximation. Due to this torque, the Janus particle will orient itself such that its cap points in the direction perpendicular to the applied field. For the torque calculated with the Maxwell Stress Tensor, we get a similar result as in the dipole approximation. On the other hand, according to the calculations with the stress tensor, there is a relatively small force on the particle. Subject Janus particlesElectrostaticsColloidal particles To reference this document use: http://resolver.tudelft.nl/uuid:098c12cc-1830-46f2-84e8-6a5a94272d77 Part of collection Student theses Document type bachelor thesis Rights © 2022 Jeroen van de Velde Files PDF BEP_report_Jeroen_van_de_Velde.pdf 2.4 MB Close viewer /islandora/object/uuid:098c12cc-1830-46f2-84e8-6a5a94272d77/datastream/OBJ/view