Emulsion microstructure and energy input, roles in emulsion stability
Emulsion microstructure and energy input, roles in emulsion stability
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DOI：
10.1016/j.colsurfa.2005.04.015
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发表时间：
2005-07-15
影响因子：
5.2
通讯作者：
McGrath, KM
中科院分区：
文献类型：
--
作者：
Liu, EH;McGrath, KM
研究了在甲苯/Triton X-100/水体系中形成的一系列水包油乳状液的微观结构随配方过程中能量输入的变化规律。对于单一的乳化组合物，只需改变乳化过程中提供的能量，即可控制乳状液的微观结构。在该体系中实现了四种不同的乳状液微观结构：两种不同的离散油滴结构(低含油量和高含油量)被双连续体系隔开，最后是含油量最高的闭孔泡沫结构。这两个离散的油滴乳状液在增加配方能量方面做出了相反的反应。对于低含油量乳状液，平均液滴直径随着能量的增加而减小，而对于高含油量乳状液，平均滴径增大。说明两种液滴乳状液的界面特征不同。奶油培养结果证实了这种分化。双连续乳状液在相图中连接了两个液滴乳状液，只能在非常低的能量输入下实现，而闭孔泡沫乳状液几乎完全独立于配方所用的能量。用不同的输入能量形成的给定乳化液组合物的流变学研究表明，只有一个响应，这是在施加外部应力时形成一种常见微结构的结果。这些结果表明，主要由Triton X-100控制的这些乳液的界面区域的强度非常弱，在配方过程中很容易操纵，但在加工过程中也是如此。(C)2005 Elsevier B.V.保留所有权利。
The microstructure of a series of oil-in-water emulsions, formed in the toluene/triton X-100/water system, was investigated as a function of energy input during the formulation process. Emulsion microstructure could be manipulated for a single emulsion composition by changing only the amount of energy supplied during emulsification. Four different emulsion microstructures are realisable in this system: two distinct discrete oil droplet structures (low- and high-oil content) separated by a bicontinuous system and finally for the highest oil content a closed-cell foam structure. The two discrete oil droplet emulsions responded in an opposite sense on increasing formulation energy. For the low-oil content droplet emulsion the average droplet diameter decreased on increasing energy input whereas the average droplet diameter for the high-oil content emulsions increased. Indicating that the interfacial characteristics of the two droplet emulsions are different. Creaming results confirmed this differentiation. The bicontinuous emulsion, which bridges the two droplet emulsions in the phase diagram, could only be realised for very low energy inputs, whereas the closed-cell foam emulsion was almost completely independent of formulation energy used. Rheological investigations of a given emulsion composition, formed with varying input energy, showed a single response only, the result of one common microstructure being formed upon application of the external stress. These results show that the strength of the interfacial domain of these emulsions, controlled primarily by the triton X-100, is extremely weak, being readily manipulable during formulation but equally so upon processing. (c) 2005 Elsevier B.V. All rights reserved.