Hydrodynamic measurement of Brownian particles at a liquid-solid interface by low-coherence dynamic light scattering.
The hydrodynamics of Brownian particles close to a wall is investigated using low-coherence dynamic light scattering. The diffusion coefficient of the particles in a suspension is measured as a function of distance from the wall. A sudden reduction in the diffusion coefficient near the interface is clearly observed using this method. The theoretically predicted wall-drag effect is experimentally confirmed when the influence of the spatial resolution due to the finite coherence length of the light source is accounted for. The space-dependent dynamics of Brownian particles under the wall-drag effect is obtained for the first time using our spatially resolved dynamic light scattering technique.
Ishii
Katsuhiro
K
Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsucho, Nishi-Ku, Hamamatsu, 4311202, Japan. ishii@gpi.ac.jp
Iwai
Toshiaki
T
Xia
Hui
H
D000465:Algorithms; D004058:Diffusion; D004867:Equipment Design; D008027:Light; D015233:Models, Statistical; D009391:Nephelometry and Turbidimetry; D055095:Optics and Photonics; D010825:Physics / Q000379:methods*; D012542:Scattering, Radiation