Dynamics and Rheology of Colloidal Ellipsoids
(2019) KEMR17 20182Department of Chemistry
- Abstract
- We present an experimental investigation of the dynamics of near-to-sphere colloidal ellipsoids in which we deploy a recently developed technique differential dynamic microscopy (DDM). Inherently opaque systems as well as progressively dense dispersions exhibit multiple scattering and as conventional techniques such as dynamic light scattering (DLS) suffer from this effect, studies probing their dynamics are limited. We show that with DDM samples of at least two orders of magnitude higher volume fractions can be analyzed than is possible with DLS. We have combined the obtained results with rheometry and analyzed the onset of the glass transition in these colloidal dispersion, additionally. We report a glass transition at a volume fraction... (More)
- We present an experimental investigation of the dynamics of near-to-sphere colloidal ellipsoids in which we deploy a recently developed technique differential dynamic microscopy (DDM). Inherently opaque systems as well as progressively dense dispersions exhibit multiple scattering and as conventional techniques such as dynamic light scattering (DLS) suffer from this effect, studies probing their dynamics are limited. We show that with DDM samples of at least two orders of magnitude higher volume fractions can be analyzed than is possible with DLS. We have combined the obtained results with rheometry and analyzed the onset of the glass transition in these colloidal dispersion, additionally. We report a glass transition at a volume fraction of ~0.64. (Less)
- Popular Abstract
- Dynamics on the colloidal length scale is ubiquitous in nature. Of particular interest is the dynamics of systems approaching a glass or a kinetically arrested state. Despite the enormous effort devoted by researchers over the past few decades to investigate the nature of the glass transition, there remain a number of open questions concerning the effects of shape anisotropy on self and collective dynamics at high packing densities. The lack of suitable model systems and the failure of classical techniques for investigating dense and often highly turbid suspensions near an arrest transition has immensely contributed towards the limited experimental information available up until now. In the present article we are able to provide a model... (More)
- Dynamics on the colloidal length scale is ubiquitous in nature. Of particular interest is the dynamics of systems approaching a glass or a kinetically arrested state. Despite the enormous effort devoted by researchers over the past few decades to investigate the nature of the glass transition, there remain a number of open questions concerning the effects of shape anisotropy on self and collective dynamics at high packing densities. The lack of suitable model systems and the failure of classical techniques for investigating dense and often highly turbid suspensions near an arrest transition has immensely contributed towards the limited experimental information available up until now. In the present article we are able to provide a model system along with a suitable technique that can be used to investigate the collective dynamics of anisotropic particles in the semi-concentrated regime.
Using the recently developed technique Differential Dynamic Microscopy (DDM), we have demonstrated that it is possible to explore the collective dynamics of well-defined colloidal ellipsoids over a concentration range no accessible to more conventional techniques. This manuscript demonstrates that DDM can now be used as a versatile technique to overcome the impediment encountered with most classical methods. We believe that DDM has the potential to result in a paradigm shift in the investigation of dynamic properties of a wide variety of synthetic and biological systems and will help in uncovering new physics that has eluded researchers due to the aforementioned technical difficulties. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8973518
- author
- Koolen, Cedric LU
- supervisor
- organization
- course
- KEMR17 20182
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Collodial ellipsoids, differential dynamic microscopy, DDM, Physical chemistry
- language
- English
- id
- 8973518
- date added to LUP
- 2023-06-28 13:26:36
- date last changed
- 2023-06-28 13:26:36
@misc{8973518,
abstract = {{We present an experimental investigation of the dynamics of near-to-sphere colloidal ellipsoids in which we deploy a recently developed technique differential dynamic microscopy (DDM). Inherently opaque systems as well as progressively dense dispersions exhibit multiple scattering and as conventional techniques such as dynamic light scattering (DLS) suffer from this effect, studies probing their dynamics are limited. We show that with DDM samples of at least two orders of magnitude higher volume fractions can be analyzed than is possible with DLS. We have combined the obtained results with rheometry and analyzed the onset of the glass transition in these colloidal dispersion, additionally. We report a glass transition at a volume fraction of ~0.64.}},
author = {{Koolen, Cedric}},
language = {{eng}},
note = {{Student Paper}},
title = {{Dynamics and Rheology of Colloidal Ellipsoids}},
year = {{2019}},
}