Tuning suspension rheology using capillary forces
Tuning suspension rheology using capillary forces
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DOI：
10.1039/c2sm25681a
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发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Willenbacher, Norbert
中科院分区：
文献类型：
--
作者：
Koos, Erin;Johannsmeier, Julia;Willenbacher, Norbert
当在悬浮液的连续相中加入少量（小于1%）的第二种不混相液体时，外加剂的流变性能发生显著变化，它可以从流体状态变为凝胶状态。通过改变颗粒大小、温度引起的界面张力变化以及添加表面活性剂，可以改变其流变性能。这些变化在目前的工作中进行了实验研究，主要集中在毛细（非润湿）状态，并在钟摆（润湿）状态下进行了额外的实验。屈服应力随界面张力和倒数半径（γ /r）的变化而变化，这是由于引力的毛细性质导致了网络的形成和凝胶化。表面活性剂的加入导致屈服应力和粘度的急剧降低，这是由于表面活性剂胶束中二次流体的部分捕获。
When a small amount (less than 1%) of a second immiscible liquid is added to the continuous phase of a suspension, the rheological properties of the admixture are dramatically altered and it can change from a fluid-like to a gel-like state. The rheological properties can be modified through changes in the particle size, temperature induced changes to the interfacial tension, and through the addition of surfactants. These changes are experimentally investigated in this current work, concentrating on the capillary (non-wetting) state with additional experiments in the pendular (wetting) state. The yield stress scales with the interfacial tension and reciprocal radius (Gamma/r) as expected due to the capillary nature of the attractive force leading to network formation and gelation. The addition of surfactants leads to a drastic reduction in the yield stress and viscosity, which is attributed to a partial trapping of the secondary fluid within surfactant micelles.