Effect of ultrasound on the pH profiles in the unstirred layers near planar bilayer lipid membranes measured by microelectrodes.
A pH shift in the unstirred layers (USLs) near a planar lipid bilayer membrane was induced by the diffusion of acetic acid along a concentration gradient. By means of a microelectrode technique it was shown that ultrasound decreases the thickness of the USL and that this reduction was much more pronounced on the side facing the ultrasound transducer than on the opposite side of the membrane. The effect depending on sound frequency and pressure is caused by the unidirectional fluid flow built up between transducer surface and membrane, the so-called quartz wind. Theoretical considerations based on the equations of the acoustic streaming near interfaces combined with the diffusion equation allow to predict the thickness of the USL if the sound field parameters are known.
Pohl
P
P
Department of Medical Physics and Biophysics, Martin Luther University, Halle, Germany.
Antonenko
Y N
YN
Rosenfeld
E
E
D000085:Acetates / Q000737:chemistry; D019342:Acetic Acid; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000737:chemistry*; D008433:Mathematics; D008564:Membrane Potentials; D008839:Microelectrodes; D014465:Ultrasonics
D000085:Acetates; D008051:Lipid Bilayers; D019342:Acetic Acid