Abstract：
Soft solid emulsions are liquid droplets encapsulated in a soft solid material. Typical of dispersed systems, they can combine properties from both the liquid inclusions and the soft solids. The relative importance of the two phases in the rheological response is captured through the elastocapillary number, which compares capillary forces in the liquid inclusions to the matrix rigidity. We work with solid emulsions formed of poly(ethylene glycol) droplets in a poly(dimethylsiloxane) (PDMS) continuous phase. We create three families of emulsions with varying elastocapillary numbers, and range of inclusion volume fractions from 0 to 0.5. Through oscillatory rheology we probe both the elastic response and the dissipative effects of liquid droplets. In the case of a dominant response from the continuous phase or the drops, the results can be described with Palierne\'s model. However, for the intermediate elastocapillary series we show that the evolution of the storage and loss moduli decouple with dispersed phase volume fraction. We attribute the increase of loss factor with volume fraction to the high polydispersity in droplet size. We can further modulate the response of the materials by cooling to freeze the droplets. This approach allows us to compare these soft solid emulsions with theories related to solid dispersions.
摘要：
软固体乳液是包封在软固体材料中的液滴。典型的分散系统，它们可以结合液体夹杂物和软固体的性质。流变响应中两个阶段的相对重要性通过弹性毛细管数捕获，它将液体夹杂物中的毛细管力与基体刚度进行了比较。我们使用由聚（二甲基硅氧烷）（PDMS）连续相中的聚（乙二醇）液滴形成的固体乳液。我们创建了三个具有不同弹性毛细管数的乳液家族，夹杂物体积分数范围从0到0.5。通过振荡流变学，我们探索了液滴的弹性响应和耗散效应。在来自连续相或液滴的主要响应的情况下，结果可以用Palierne的模型来描述。然而,对于中间弹性毛细管系列，我们表明存储和损耗模量的演变与分散相体积分数解耦。我们将损耗因子随体积分数的增加归因于液滴尺寸的高多分散性。我们可以通过冷却以冷冻液滴来进一步调节材料的响应。这种方法使我们能够将这些软固体乳液与与固体分散体相关的理论进行比较。
