论文标题
颗粒夹杂物对胶体凝胶相行为的影响
Impact of granular inclusions on the phase behavior of colloidal gels
论文作者
论文摘要
由小型颗粒形成的胶体凝胶通常用于制剂中，以使较大的组件保持悬浮液。然而，尽管表征了未填充的凝胶的大量工作，但对较大的夹杂物如何改变胶体系统的相位行为和微观结构知之甚少。在这里，我们使用数值模拟来检查较大的“颗粒”颗粒如何改变凝胶过渡相边界。我们发现了两个不同的机制，具体取决于填充物的大小和本机凝胶结构：一个“被动”制度，其中填充物适合已经存在的空隙，几乎没有变化，而过渡方案几乎没有变化，而“主动”方案不再适合这些空隙，而是将本机结构固定在这些空隙中。在第二个体制中，相边界由可用自由体积给出的有效胶体体积分数控制。
Colloidal gels formed from small attractive particles are commonly used in formulations to keep larger components in suspension. However, despite extensive work characterizing unfilled gels, little is known about how larger inclusions alter the phase behavior and microstructure of the colloidal system. Here we use numerical simulations to examine how larger `granular' particles can alter the gel transition phase boundaries. We find two distinct regimes depending on both the filler size and native gel structure: a `passive' regime where the filler fits into already-present voids, giving little change in the transition, and an `active' regime where the filler no longer fits in these voids and instead perturbs the native structure. In this second regime the phase boundary is controlled by an effective colloidal volume fraction given by the available free volume.
