Visualisation of foam microstructure when subject to pressure change
Visualisation of foam microstructure when subject to pressure change
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DOI：
10.1016/j.colsurfa.2007.06.004
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发表时间：
2007-12
期刊：
影响因子：
--
通讯作者：
A. Heuer;A. Cox;S. Singleton;M. Barigou;M. Ginkel
中科院分区：
文献类型：
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作者：
A. Heuer;A. Cox;S. Singleton;M. Barigou;M. Ginkel
我们报告了一种方法的发展，以研究静态和动态的影响，压力对气泡的稳定性聚结的过程和配方制度，是相关的食品工业。在这项初步工作中，使用Linkam压力单元和通过共聚焦扫描激光显微镜（CSLM）对泡沫进行直接原位成像的组合来研究模型食品泡沫。在压力从11巴绝对值变化到1巴、从11巴变化到6巴和从6巴变化到1巴的过程中进行观察，并捕获泡沫微观结构的变化。然后使用获得的数字图像的分析来量化压力对气泡尺寸分布的影响。所获得的结果表明，所研究的泡沫在静态条件下是相对稳定的，但当受到类似于典型工业过程的压力变化时，可能会不稳定。施加到泡沫的压力变化越大，导致的聚结越多。然而，大多数聚结事件发生在一个小的压力窗口。通过压力变化导致的气泡尺寸分布的变化必须与空气/水表面的性质以及这如何响应表面积的变化直接相关。它也可能与作为动态变化函数的气体在连续相中的溶解度有关。
We report the development of a methodology to study the static and dynamic effects of pressure on the stability of air bubbles to coalescence in process and formulation regimes that are relevant to much of the food industry. In this initial work a model food foam was studied using a combination of a Linkam pressure cell and direct in situ imaging of the foam by confocal scanning laser microscopy (CSLM). Observations were made during pressure changes from 11bar absolute to 1bar, from 11 to 6bar, and from 6 to 1bar and the resulting changes in the foam microstructure were captured. Analysis of the digital images obtained was then used to quantify the effects of pressure on bubble size distribution. The results obtained show that the foam under study was relatively stable under quiescent conditions but could de-stabilise when subject to a pressure change similar to that of a typical industrial process. The larger the pressure change that was applied to the foam, the more coalescence resulted. However, most of the coalescence events were noted to take place over a small pressure window. The resulting change in the air bubble size distribution through pressure changes must be directly related to the nature of the air/water surface and how this responds to a change in surface area. It is also likely to relate to the solubility of the gas in the continuous phase as a function of dynamic change.