Résumé des résultats (Abstract)
(Anglais)
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It is a central observation in nature that on changing some parameters of the system, molecules, particles, or more complex aggregates in a fluid can simply stop moving (or almost so) in a concerted manner, without leading to an ordered state of matter such as a crystal. This is a ubiquitous phenomenon that we term 'dynamical arrest'. Its existence has been known for many years in some parts of condensed matter science, but its relevance for soft matter and complex biomatter has just now begun to be appreciated. There is now good scientific reason to believe that there exist central paradigms, that will unify descriptions of 'gels', aggregates, amorphous solids, jammed substances and glasses, providing a rational basis to understand states of matter that have often been viewed as unsuitable for deep scientific study. With such a study it may in future be possible to 'design' material states, ore use 'knowledge' to create novel materials. Thus, sometimes arrested states of soft and colloidal matter are of considerable value, being important in food, biomedical and materials research, whereas in other situations (as for example in the formation of globular protein crystals or crystals on optical length-scales) it is the high quality crystal that we seek to make overcoming the competition of arrest. To be able to select one rather than the other (on a rational basis) would be a great practical achievement. In this project we will establish the important dynamical motions in a liquid, just prior to arrest, developing or adapting novel experimental techniques that have a wider application in soft nano- and meso-particle science in dense dispersions. We will develop an understanding of the fundamental principles of concerted arrest, and establish the rational basis for understanding the arrested states of matter in soft matter and colloidal science.
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