Measurement of dynamical forces between deformable drops using the atomic force microscope. I. Theory.
Recent experimental developments have enabled the measurement of dynamical forces between two moving liquid drops in solution using an atomic force microscope (AFM). The drop sizes, interfacial tension, and approach velocities used in the experiments are in a regime where surface forces, hydrodynamics, and drop deformation are all significant. A detailed theoretical model of the experimental setup which accounts for surface forces, hydrodynamic interactions, droplet deformation, and AFM cantilever deflection has been developed. In agreement with experimental observations, the calculated force curves show pseudo-constant compliance regions due to drop flattening, as well as attractive pull-off forces due mainly to hydrodynamic lubrication forces.
Carnie
Steven L
SL
Department of Mathematics and Statistics, Particulate Fluids Processing Centre, University of Melbourne, Parkville 3010, Australia. s.carnie@ms.unimelb.edu.au
Chan
Derek Y C
DY
Lewis
Craig
C
Manica
Rogério
R
Dagastine
Raymond R
RR