论文标题
与非粘颗粒的胶体凝胶化
Colloidal Gelation with Non-Sticky Particles
论文作者
论文摘要
胶体凝胶由于其流变特性而广泛应用于行业 - 没有流动的流量低于屈服应力。这种特性使凝胶能够在实际配方中保持均匀的分布；否则，固体组件可能会在没有凝胶基质的支持的情况下迅速沉积。因此，与粘性胶体的纯凝胶相比，凝胶和非粘性夹杂物的复合材料在现实中更常见。通过数值模拟，我们研究了此类二进制复合材料中的凝胶化过程。我们发现，非粘性颗粒不仅以有效体积分数的形式限制凝胶化，而且还引入了另一个长度尺寸，该长度尺寸与凝胶中不断增长的簇的大小竞争。通常控制两个效果的两个键长度的比率。使用不同的凝胶模型，我们在广泛的参数空间内验证了这种情况，这表明在所有类别的胶体复合材料中都有潜在的普遍性。
Colloidal gels are widely applied in industry due to their rheological character -- no flow takes place below the yield stress. Such property enables gels to maintain uniform distribution in practical formulations; otherwise, solid components may quickly sediment without the support of gel matrix. Compared with pure gels of sticky colloids, therefore, the composites of gel and non-sticky inclusions are more commonly encountered in reality. Through numerical simulations, we investigate the gelation process in such binary composites. We find that the non-sticky particles not only confine gelation in the form of an effective volume fraction, but also introduce another lengthscale that competes with the size of growing clusters in gel. The ratio of two key lengthscales in general controls the two effects. Using different gel models, we verify such a scenario within a wide range of parameter space, suggesting a potential universality in all classes of colloidal composites.
