Schematic of the annular deep-channel surface viscometer and data acquisition system.
Measured equation of state for DPPC on pure water 27 in terms of surface pressure (reduction in the surface tension from that of a clean surface, about 72.3 dyne/cm at 22 °C) and area coverage. The BAM images, obtained at 45× magnification using an objective with NA = 0.28 (resolving power of 1.1 μm), show co-existing LE/LC phase domains in the intermediate range of monolayer concentration.
Comparison between our measured equation of state (shown in Fig. 2 ) with data from the literature.
Non-dimensionalized surface azimuthal velocity profile as measured in our apparatus using conventional particle tracking and cross correlated BAM images for and Π = 5 dyne/cm. For all BAM measurements presented here and in Figs. 5 and 6 , the magnification was 7× with resolving power of 3 μm.
Azimuthal velocity profiles at the air/water surface for Re = 100; the experimentally measured profiles are shown as symbols at the surface pressures Π as indicated; the corresponding area per molecule are 0.79 nm2, 0.54 nm2, 0.51 nm2, 0.48 nm2, and 0.45 nm2. The lines are computed profiles with non-dimensional surface shear viscosity μ s /μr o as indicated.
Same as in Fig. 5 , except for Re = 600.
Surface shear viscosity of DPPC, μ s , as determined from flows at Re = 100 and Re = 600, versus surface pressure Π. Also shown are μ s from other experimental measurements. 9,39
Article metrics loading...
Full text loading...