Measurement of the velocity profile of a dilute polymer solution in a microchannel using evanescent wave illumination

摘要

The velocity profile of a dilute polymer solution and a distilled water near the wall surface in a microchannel was clarified using a particle tracking velocimetry technique combined with evanescent wave illumination. Fluorescent particles with a diameter of 100 nm were used as tracer particles. The test polymer is polyethylene-oxide (Peol5) solution at 5 ppm. The results obtained for the velocity profile of distilled water was found to agree well with the two-dimensional Poiseuille velocity profile at 100 nm < z < 250 nm. On the other hand, the velocity profile of the dilute polymer solution decreases significantly compared with that of a distilled water within 250 nm of the wall surface.