An oscillating bubble technique to determine surfactant mass transfer kinetics

A Theoretical Model of Pulmonary Surfactant Multilayer Collapse under Oscillating Area Conditions

“…This model has been developed to quantify concepts developed over decades of experimental research of the behavior of surfactant in the pulmonary system. Under low concentration conditions, the present model contains kinetics (adsorption/desorption and diffusion) similar as to those of previous models for determining surfactant hysteresis in an oscillating bubble system (17,21,22). However, while Horn and Davis (23) pinpointed viscoelasticity of the interface as the most probable cause of P-V hysteresis, that study did not consider the effects of collapse and respreading, which can be extremely important (2,16).…”

“…The tolerance criterion is met if |x new − x old | ≤ tol rel |x new | + tol abs , [22] where x is the characteristic under consideration. Thus, in the limit of small x new , this test reverts to an absolute tolerance test which is a little less sensitive to numerical noise.…”

Measurements of the Surface Elasticity in Medium Frequency Range Using the Oscillating Bubble Method

“…Two different principles of this method are known: first, the excitation via an air chamber and second, the excitation via a fluid chamber. The first version was built by Lunkenheimer (56 -59) according to the theoretical outlines proposed by Wantke (56 -59), and later by Johnson and Stebe (20,47,48), as well by Karapantsios and Palmer (55). Examples for the second version are the method of Enhorning (49,60) and the setup of Fruhner (13,54).…”

“…However, for more highly concentrated solutions the oscillating bubble method leads to much better results in the medium-frequency range because the simple flux behavior allows an easy elimination of the bulk influence. For this reason, some groups have improved the oscillating bubble method (13,20,21,(47)(48)(49)(50)(51)(52)(53)(54)(55). This method enables the determination of ⑀( f, c) in a broader frequency range with little effort.…”

A study of kinetic molecular exchange processes in the medium frequency range by surface SHG on an oscillating bubble

“…It is introduced for formal reasons to characterize the influence of dissipative losses within the surface layer on the surface tension. Experimental results request this term [8][9][10][11][12][13][14]. Here we consider only the compositional effects because the solution used shows no influence of an intrinsic surface dilatational viscosity (κ = 0).…”