Author : Brian David Leahy
Publisher :
ISBN 13 :
Total Pages : 512 pages
Book Rating : 4.:/5 (1 download)
Book Synopsis Orientation Dynamics and Microscope Imaging of Colloidal Suspensions by : Brian David Leahy
Download or read book Orientation Dynamics and Microscope Imaging of Colloidal Suspensions written by Brian David Leahy and published by . This book was released on 2016 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micron-sized colloidal particles provide a unique window into the workings of statistical mechanics. These particles are large enough to be easily imaged with a microscope, allowing for detailed, mechanistic testing of statistical theories, yet small enough to still feel the effects of Brownian motion and thermal forces. Moreover, these thermal forces result in dynamics that are controlled by energy scales at room temperature and time scales on the order of seconds. In addition to allowing detailed control over a colloidal suspension, these accessible scales allow for the possibility of driving the suspension far from equilibrium and the exploration of non-equilibrium statistical mechanics. Much work has focused on the behavior of spherical colloidal particles, which lack an orientational degree of freedom and have simpler dynamics. However, many real suspensions are composed of particles with an orientational degree of freedom. In this thesis I explore the dynamics of dilute suspensions of nonspherical colloidal particles far from equilibrium. First, using an experiment I show that the rotational diffusivity of rodlike colloidal particles is enhanced under shear. Second, using a simplified theory I analytically solve for these dynamics far from equilibrium (in the limit of large Péclet numbers). The e diffusivity is enhanced at a rate proportional to the square of the particle's aspect ratio. Interestingly, this solution also provides insight into the oscillatory shear dynamics of these particles, and into the continuous and oscillatory shear rheology of these suspensions. Third, I use this solution to control the alignment and rheology of a suspension of particles. Finally, I close by improving the microscope's resolution by 10-100x through image analysis alone, without modifying the microscope itself. By improving the resolution we expect to be able to see new dynamics of colloidal particles at unprecedented scales.