Picard Cyril, Davoust Laurent
UMR LEGI, CNRS, Microfluidics, Interfaces & Particles Team, BP 53, 38041 Grenoble cedex 9, France.
J Colloid Interface Sci. 2008 Nov 15;327(2):412-25. doi: 10.1016/j.jcis.2008.08.032. Epub 2008 Aug 22.
This article discusses the aging of a liquid surface enriched with surface active species and suddenly perturbed by standing capillary waves. Special attention is paid to deriving an accurate initial condition of the surface elevation. Due to the arising of the waves, the sub-phase and surface concentrations, C and Gamma, which were initially uniform and controlled by thermodynamic equilibrium, are modified by a transient oscillatory regime. A complete analytical description of the time-dependent carrier wave and oscillating chemical modulations associated with these concentrations is proposed for: (1) a small surface elevation, (2) a weak coupling with momentum transport, (3) but a strong coupling between all chemical transport phenomena which might be involved during transient regime: surface adsorption/desorption, 3-D diffusion within the sub-phase as well as near the liquid surface, and 2-D chemical diffusion along the surface. Analytical expressions resulting from regular perturbation series are compared to the limit aging regimes most commonly invoked in the literature, namely, diffusion- or sorption-limited surface aging. Finally, the (surface) compositional elasticity due to the arising of surface tension gradients is derived.
本文讨论了富含表面活性物质的液体表面因驻波毛细波而突然受到扰动时的老化情况。特别关注推导表面高度的精确初始条件。由于波的产生，最初由热力学平衡控制的均匀的亚相浓度和表面浓度C和Gamma，会被一个瞬态振荡状态所改变。针对以下情况，提出了与这些浓度相关的随时间变化的载波和振荡化学调制的完整解析描述：（1）小表面高度；（2）与动量传输的弱耦合；（3）但在瞬态状态下可能涉及的所有化学传输现象之间的强耦合：表面吸附/解吸、亚相内以及液体表面附近的三维扩散，以及沿表面的二维化学扩散。将正则摄动级数得到的解析表达式与文献中最常引用的极限老化状态进行了比较，即扩散或吸附限制的表面老化。最后，推导了由于表面张力梯度的产生而导致的（表面）成分弹性。
