(42g) Direct Measurement of Diffusiophoretic Velocity of Colloidal Particles
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Engineering Sciences and Fundamentals
Novel Experimental Methods for the Study of Interfacial Phenomena
Sunday, October 28, 2018 - 5:00pm to 5:15pm
Diffusiophoresis is the motion of a colloidal particle in a gradient of a solute with which the surface of the particle has an interaction. The measurement of the velocity of this motion is of importance to both fundamental studies as well as in applications such as sperm motility, chemotaxis, enhancement of mass-transfer, etc. Thus far, the diffusiophoretic velocity has not been directly measured and validated against theory without relying on some fitting parameter. We present a simple device and a principle to measure the velocity directly under a microscope. We also show that the measured velocity agrees reasonably with independent theoretical estimates.