Adhesion of bubbles and drops to solid surfaces, and anisotropic surface tensions studied by capillary meniscus dynamometry
Adhesion of bubbles and drops to solid surfaces, and anisotropic surface tensions studied by capillary meniscus dynamometry
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DOI：
10.1016/j.cis.2015.06.003
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发表时间：
2016-07-01
影响因子：
15.6
通讯作者：
Pelan, Eddie G.
中科院分区：
文献类型：
--
作者：
Danov, Krassimir D.;Stanimirova, Rumyana D.;Pelan, Eddie G.
在这里，我们回顾了最近开发的两种方法的原理和应用：毛细管弯月面测力法（CMD）用于测量气泡/液滴的表面张力，和毛细管桥测力法（CBD）用于量化气泡/液滴粘附到固体表面。这两种方法都是基于一个新的数据分析协议，它允许一个解耦的两个组件的非各向同性表面张力。对于轴对称的非流体界面（例如，由具有剪切弹性的蛋白质吸附层覆盖的气泡或液滴），CMD确定各向异性表面张力的两个不同分量as和Gip，其沿着“子午线”和“平行线”作用，并且在整个界面上变化。该方法使用瞬时气泡（液滴）轮廓和毛细管压力的数据，但数据处理的程序是本质上不同于传统的液滴形状分析（DSA）方法。在气泡或液滴压在基底上形成毛细桥的情况下，CBD方法还允许确定各向同性（流体）和各向异性（固化）吸附层的毛细桥力。气泡（液滴）从基底上脱离的实验表明，存在一个最大的拉力，F-max，可以抵抗粘附的流体颗粒。F-max可用于量化气泡和液滴与固体表面的粘附强度。它的值是由吸引横向张力和排斥分离压力的竞争决定的。最大的F-max值已被测量的气泡粘附到玻璃基板在豌豆蛋白质的解决方案。在含有蛋白质HFB II疏水蛋白的溶液中，气泡/壁粘附性较低，这可以用夹心蛋白质聚集体的效果来解释。CBD方法的乳液系统的适用性说明了通过实验与大豆油滴粘附在蛋黄溶液中的亲水性和疏水性基板。结果揭示了界面刚性，以及气泡/壁和液滴/壁粘附力，可以量化和控制有关的泡沫和乳液的性能优化。(C)2015爱思唯尔B. V.保留所有权利。
Here, we review the principle and applications of two recently developed methods: the capillary meniscus dynamometry (CMD) for measuring the surface tension of bubbles/drops, and the capillary bridge dynamometry (CBD) for quantifying the bubble/drop adhesion to solid surfaces. Both methods are based on a new data analysis protocol, which allows one to decouple the two components of non-isotropic surface tension. For an axisymmetric non-fluid interface (e.g. bubble or drop covered by a protein adsorption layer with shear elasticity), the CMD determines the two different components of the anisotropic surface tension, as and Gip, which are acting along the "meridians" and "parallels", and vary throughout the interface. The method uses data for the instantaneous bubble (drop) profile and capillary pressure, but the procedure for data processing is essentially different from that of the conventional drop shape analysis (DSA) method. In the case of bubble or drop pressed against a substrate, which forms a capillary bridge, the CBD method allows one to determine also the capillary-bridge force for both isotropic (fluid) and anisotropic (solidified) adsorption layers. The experiments on bubble (drop) detachment from the substrate show the existence of a maximal pulling force, F-max, that can be resisted by an adherent fluid particle. F-max can be used to quantify the strength of adhesion ofbubbles and drops to solid surfaces. Its value is determined by a competition of attractive transversal tension and repulsive disjoining pressure forces. The greatest F-max values have been measured for bubbles adherent to glass substrates in pea-protein solutions. The bubble/wall adhesion is lower in solutions containing the protein HFBII hydrophobin, which could be explained with the effect of sandwiched protein aggregates. The applicability of the CBD method to emulsion systems is illustrated by experiments with soybean-oil drops adherent to hydrophilic and hydrophobic substrates in egg yolk solutions. The results reveal how the interfacial rigidity, as well as the bubble/wall and drop/wall adhesion forces, can be quantified and controlled in relation to optimizing the properties of foams and emulsions. (C) 2015 Elsevier B.V. All rights reserved.