Anisotropic diffusion of spherical particles in closely confining microchannels
| Autor: | Stefano Pagliara, Ulrich F. Keyser, Karolis Misiunas, Simon L. Dettmer |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Materials science
Yield (engineering) Anisotropic diffusion Finite Element Analysis Microfluidics FOS: Physical sciences Nanotechnology Condensed Matter - Soft Condensed Matter Thermal diffusivity 01 natural sciences Molecular physics 010305 fluids & plasmas Diffusion 0103 physical sciences Perpendicular Computer Simulation Particle Size Diffusion (business) 010306 general physics Anisotropy Brownian motion Fluid Dynamics (physics.flu-dyn) Physics - Fluid Dynamics Soft Condensed Matter (cond-mat.soft) Polystyrenes Particle size |
| Zdroj: | Physical Review E |
| ISSN: | 1539-3755 |
| DOI: | 10.1103/PhysRevE.89.062305 |
| Popis: | We present here the measurement of the diffusivity of spherical particles closely confined by narrow microchannels. Our experiments yield a two-dimensional map of the position-dependent diffusion coefficients parallel and perpendicular to the channel axis with a resolution down to 129 nm. The diffusivity was measured simultaneously in the channel interior, the bulk reservoirs, as well as the channel entrance region. In the channel interior we found strongly anisotropic diffusion. While the perpendicular diffusion coefficient close to the confining walls decreased down to approximately 25% of the value on the channel axis, the parallel diffusion coefficient remained constant throughout the entire channel width. In addition to the experiment, we performed finite element simulations for the diffusivity in the channel interior and found good agreement with the measurements. Our results reveal the distinctive influence of strong confinement on Brownian motion, which is of significance to microfluidics as well as quantitative models of facilitated membrane transport. Comment: 8 pages, 6 figures |
| Databáze: | OpenAIRE |
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