Morphology and rheology of ternary fluid–fluid–solid systems
Morphology and rheology of ternary fluid–fluid–solid systems
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DOI：
10.1039/c2sm25758k
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发表时间：
2012-07
期刊：
影响因子：
3.4
通讯作者：
Shailesh P. Nagarkar;S. Velankar
中科院分区：
文献类型：
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作者：
Shailesh P. Nagarkar;S. Velankar
我们研究的影响，界面活性粒子的不混溶的均聚物的共混物与液滴/矩阵形态。颗粒对液滴尺寸的影响并不是单调的：在低体积分数（≤ 0.1%）下，颗粒通过促进流动诱导的聚结而大大增加了分散相的尺寸，而不管哪一相优先润湿颗粒。在较高的颗粒负载量（~ 1vol%）下，颗粒完全覆盖界面并减小分散相的尺寸。优先被连续相润湿的颗粒也能够通过桥接两个液滴而将它们粘合在一起。在这种情况下，形态由颗粒桥接的液滴的簇组成，并且所得共混物显示固体状流变性。在低颗粒负载下，大部分颗粒夹在液滴之间，使界面的其余部分无颗粒。在高颗粒负载下，整个表面几乎被颗粒覆盖，液滴是多面的，并且形态类似于泡沫结构。与这些结果相反，被分散相优先润湿或被两相同等润湿的颗粒不能桥接，并且这些共混物不显示液滴簇。这些结果提供了新的见解的行为的三元系统组成的两种流体和一个颗粒物种。
We examine the effects of interfacially active particles in blends of immiscible homopolymers with a droplet/matrix morphology. The effect of particles on drop size is not monotonic: at low volume fractions (∼0.1%), particles greatly increase the size of the dispersed phase by promoting flow-induced coalescence regardless of which phase wets the particles preferentially. At higher particle loadings (∼1 vol%), the particles completely cover the interface and reduce the size of the dispersed phase. Particles that are preferentially wetted by the continuous phase are also able to glue together two drops by bridging across them. In this case the morphology consists of clusters of particle-bridged drops, and the resulting blends show solid-like rheology. At low particle loadings, most of the particles are sandwiched between drops, leaving the rest of the interface particle-free. At high particle loadings, the entire surface is nearly covered with particles, the drops are faceted, and the morphology resembles a foam structure. In contrast to these results, particles that are preferentially wetted by the dispersed phase or equally wetted by both phases are not capable of bridging, and these blends do not show drop clusters. These results offer new insights on the behavior of ternary systems composed of two fluids and one particulate species.