Dynamic forces between two deformable oil droplets in water.
The understanding of static interactions in colloidal suspensions is well established, whereas dynamic interactions more relevant to biological and other suspended soft-matter systems are less well understood. We present the direct force measurement and quantitative theoretical description for dynamic forces for liquid droplets in another immiscible fluid. Analysis of this system demonstrates the strong link between interfacial deformation, static surface forces, and hydrodynamic drainage, which govern dynamic droplet-droplet interactions over the length scale of nanometers and over the time scales of Brownian collisions. The results and analysis have direct bearing on the control and manipulation of suspended droplets in soft-matter systems ranging from the emulsions in shampoo to cellular interactions.
Dagastine
Raymond R
RR
Particulate Fluids Processing Center, University of Melbourne, Victoria 3010, Australia.
Manica
Rogério
R
Carnie
Steven L
SL
Chan
D Y C
DY
Stevens
Geoffrey W
GW
Grieser
Franz
F