Kovalchuk V I, Krägel J, Makievski A V, Loglio G, Ravera F, Liggieri L, Miller R
Institute of Biocolloid Chemistry, Ukrainian National Academy of Sciences, 42 Vernadsky Avenue, Kiev 03142, Ukraine.
J Colloid Interface Sci. 2002 Aug 15;252(2):433-42. doi: 10.1006/jcis.2002.8506.
The amplitude- and phase-frequency characteristics of oscillating bubble systems with a closed measuring cell are analyzed. The shape of the frequency characteristics is qualitatively different for bubbles smaller or larger than a hemisphere, respectively, and also for diluted and concentrated surfactant solutions. Moreover, the presence of a surfactant in the solution strongly influences the characteristic frequencies of the system. The experiments performed under ground and microgravity conditions show a good qualitative agreement with theoretically predicted amplitude- and phase-frequency characteristics and confirm the adequacy of the proposed theory. The comparison of high-frequency limits of the surface dilatational elasticity with the theoretical Gibbs elasticities calculated according to the respective adsorption isotherm shows good agreement for small surfactant concentrations. At higher concentrations large discrepancies are observed which can possibly be explained by the violation of the linearity condition for the surface layer.
分析了具有封闭测量单元的振荡气泡系统的振幅和相频特性。对于小于或大于半球形的气泡，以及稀释和浓缩的表面活性剂溶液，频率特性的形状在定性上是不同的。此外，溶液中表面活性剂的存在强烈影响系统的特征频率。在地面和微重力条件下进行的实验与理论预测的振幅和相频特性显示出良好的定性一致性，并证实了所提出理论的充分性。将表面扩张弹性的高频极限与根据各自吸附等温线计算的理论吉布斯弹性进行比较，结果表明在低表面活性剂浓度下两者吻合良好。在较高浓度下，观察到较大差异，这可能是由于表面层线性条件的破坏所致。
