Non-Equilibrium Dynamics of Driven and Confined Colloidal Systems
[eng] In this thesis, I study the behavior of confined colloidal particles in aqueous suspension driven through an optical potential. For this purpose, I use micro-meter polystyrene particles, which I confine in the optical potential created with a system of optical tweezers. With the help of an Aco...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/201205 |
| Acceso en línea: | https://hdl.handle.net/2445/201205 http://hdl.handle.net/10803/688857 |
| Access Level: | acceso abierto |
| Palabra clave: | Col·loides Suspensions (Química) Solitons Colloids Suspensions (Chemistry) |
| Sumario: | [eng] In this thesis, I study the behavior of confined colloidal particles in aqueous suspension driven through an optical potential. For this purpose, I use micro-meter polystyrene particles, which I confine in the optical potential created with a system of optical tweezers. With the help of an Acousto Optical Deflector (AOD), which varies the laser position at a high frequency, I can create multiple quasi-simultaneous optical traps. This way, I can easily manipulate the particles and define the desired experimental conditions for the potential. I record videos of the particles' dynamics using optical microscopy. Thus, I obtain position information over time, which allows me to extract the necessary data to analyze the mechanisms that develop during forced transport. The results presented in this thesis expose the importance of Hydrodynamic Interactions (HI) when the transport of particles occurs due to a fluid drag. In addition, different situations are compared, including the change in the relative particle size concerning the separation between potential wells. In addition, I present a study on the emergence of solitons propagating in the opposite direction to the drag force. This situation, which appears when the experimental system is overcrowded, presents a mechanism where the transport dynamics accelerate, increasing the systems' efficiency. |
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