Projects per year
Abstract
Colloidal particles partially coated with platinum and dispersed in H2O2 solution are often used as model self-propelled colloids. Most current data suggest that neutral self-diffusiophoresis propels these particles. However, several studies have shown strong ionic effects in this and related systems, such as a reduction of propulsion speed by salt. We investigate these ionic effects in Pt-coated polystyrene colloids, and find here that the direction of propulsion can be reversed by addition of an ionic surfactant, and that although adding pH neutral salts reduces the propulsion speed, adding the strong base NaOH has little effect. We use these data, as well as measured reaction rates, to argue against propulsion by either neutral or ionic self-diffusiophoresis, and suggest instead that the particle's propulsion mechanism may in fact bear close resemblance to that operative in bimetallic swimmers.
Original language | English |
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Pages (from-to) | 4016-4027 |
Number of pages | 12 |
Journal | Soft Matter |
Volume | 10 |
Issue number | 22 |
Early online date | 11 Apr 2014 |
DOIs | |
Publication status | Published - 14 Jun 2014 |
Keywords / Materials (for Non-textual outputs)
- HYDROGEN-PEROXIDE SOLUTIONS
- ELECTROCHEMICAL OXIDATION
- CATALYTIC DECOMPOSITION
- PLATINUM-ELECTRODES
- OXYGEN REDUCTION
- ACIDIC MEDIA
- SURFACES
- ADSORPTION
- PROPULSION
- MECHANISM
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Dive into the research topics of 'Ionic effects in self-propelled Pt-coated Janus swimmers'. Together they form a unique fingerprint.Projects
- 2 Finished
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PHYSAPS: The Physics of Active Particle Suspensions
Poon, W. (Principal Investigator)
1/02/14 → 31/01/20
Project: Research
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Design Principles for New Soft Materials
Cates, M. (Principal Investigator), Allen, R. (Co-investigator), Clegg, P. (Co-investigator), Evans, M. (Co-investigator), MacPhee, C. (Co-investigator), Marenduzzo, D. (Co-investigator) & Poon, W. (Co-investigator)
7/12/11 → 6/06/17
Project: Research
Profiles
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Aidan Brown
- School of Physics and Astronomy - Chancellor's Fellow: Food and Rheology
Person: Academic: Research Active (Research Assistant)
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Wilson Poon
- School of Physics and Astronomy - Chair in Natural Philosophy
Person: Academic: Research Active