论文标题
Marangoni中的指法不稳定在深层聚合物溶液上扩散
Fingering instability in Marangoni spreading on a deep layer of polymer solution
论文作者
论文摘要
由于复杂的液体的广泛存在，在自然界和工业上散布在复杂的液体的自由表面上是普遍存在的。在这里，我们报告了在Marangoni在深层聚合物溶液上扩散过程中发展的指法不稳定。特别是，波长取决于分子量和聚合物溶液的浓度。我们使用传输晶格方法来表征微米尺度的手指高度。我们对散布半径（涉及粘弹性和剪切变薄效应）的演变进行建模，以提出比牛顿流体扩散更广泛的法律。我们对指法不稳定性的起源给出了物理解释，这是因为高剪切速率下的正常应力会在前缘产生高接触角和变形，因此选择指法不稳定性的波长。了解扩散机制在气道药物输送以及具有模式的表面涂层中具有特殊意义。
Spreading on the free surface of a complex fluid is ubiquitous in nature and industry, owing to the wide existence of complex fluids. Here we report on a fingering instability that develops during Marangoni spreading on a deep layer of polymer solution. In particular, the wavelength depends on molecular weight and concentration of the polymer solution. We use the Transmission Lattice Method to characterize the finger height at the micron scale. We model the evolution of spreading radius, involving viscoelastic and shear thinning effects, to suggest a more generalized law than the spreading of Newtonian fluids. We give physical explanation on the origin of the fingering instability as due to normal stresses at high shear rate generating high contact angle and deformation at the leading edge, and so selects the wavelength of the fingering instability. Understanding the spreading mechanism has particular implication in airway drug delivery, and surface coating with patterns.
