Usta O Berk, Perchak Dennis, Clarke Andrew, Yeomans Julia M, Balazs Anna C
Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
J Chem Phys. 2009 Jun 21;130(23):234905. doi: 10.1063/1.3153922.
We investigate the effects of polymer chains and nanoparticles on the deformation of a droplet in shear and extensional flow using computational modeling that accounts for both the solid and fluid phases explicitly. We show that under shear flow, both the nanoparticles and the encapsulated polymers reduce the shear-induced deformation of the droplet at intermediate capillary numbers. At high capillary numbers, however, long polymer chains can induce the breakup of the droplet. We find that the latter behavior is dependent on the nature of the imposed flow. Specifically, under extensional flow, long polymers inhibit the droplet breakup and reduce deformation. Overall, the findings provide guidelines for tailoring the stability of filled droplets under an imposed flow, and thus, the results can provide useful design rules in a range of technological applications.
我们使用明确考虑固相和流体相的计算模型，研究了聚合物链和纳米颗粒对液滴在剪切流和拉伸流中变形的影响。我们表明，在剪切流下，纳米颗粒和包封的聚合物在中等毛细管数下均会降低液滴的剪切诱导变形。然而，在高毛细管数下，长聚合物链会导致液滴破裂。我们发现后一种行为取决于所施加流动的性质。具体而言，在拉伸流下，长聚合物会抑制液滴破裂并减少变形。总体而言，这些发现为在施加流动下调整填充液滴的稳定性提供了指导方针，因此，结果可为一系列技术应用提供有用的设计规则。
