(27g) Understanding and Engineering Diffusiophoretic Suspensions
AIChE Annual Meeting
2017
2017 Annual Meeting
Engineering Sciences and Fundamentals
In Honor of Dennis Prieve's Retirement I (Invited Talks)
Sunday, October 29, 2017 - 5:21pm to 5:39pm
The long history of diffusiophoresis owes much to Dennis Prieve and co-workers, who developed elegant theoretical expressions, membrane deposition experiments that supported these theories, and enabled quantitative prediction of diffusiophoretic phenomena for various purposes. Our lab has developed a microfluidic technique to design and control compositional gradients across suspensions, and to directly measure the diffusiophoretic migration that results from these gradients. This technique has revealed both quantitative agreement for existing theories, and qualitative surprises in new systems. We will describe diffusiophoretic migration under some unorthodox gradients - including solvents, ionic surfactants, zwitterions, and reacting solutes. We will present a generalized theory that reproduces Prieve & Andersonâs original expressions for diffusiophoresis, but also reveals connections to other phoretic migrations, and which explain some of the surprises we have observed in our experiments. Finally, we will describe our efforts to engineer âsoluto-inertialâ interactions in suspensions, in which we engineer âbeaconâ particles that emit long-lived, long-ranged chemical fluxes, driving neighboring particles into diffusiophoretic migration. Building on Prieveâs fundamental insights about diffusiophoresis in this way, we envision versatile new capabilities for `smart suspensionsâ.