posted on 2021-06-10, 17:08authored byJesse
F. Collis, Selim Olcum, Debadi Chakraborty, Scott R. Manalis, John E. Sader
The
Navier slip condition describes the motion of a liquid relative
to a neighboring solid surface, with its characteristic Navier slip
length being a constitutive property of the solid–liquid interface.
Measurement of this slip length is complicated by its small magnitude,
expected to be in the nanometer range based on molecular simulations.
Here, we report an experimental technique that interrogates the Navier
slip length on individual nanoparticles immersed in liquid with subnanometer
precision. Proof-of-principle experiments on individual, citrate-stabilized,
gold nanoparticles in water give a constant slip length of 2.7 ±
0.6 nm (95% C.I.), independent of particle size. Achieving this feature
of size independence is central to any measurement of this constitutive
property, which is facilitated through the use of individual particles
of varying radii. This demonstration motivates studies that can now
validate the wealth of existing molecular simulation data on slip.