Response of Soft Continuous Structures and Topological Defects to a Temperature Gradient
Response of Soft Continuous Structures and Topological Defects to a Temperature Gradient
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DOI：
10.1103/physrevlett.119.108003
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发表时间：
2017-09-08
影响因子：
8.6
通讯作者：
Tanaka, Hajime
中科院分区：
文献类型：
--
作者：
Kurita, Rei;Mitsui, Shun;Tanaka, Hajime
热泳是由温度梯度引起的质量传输，作为一种新的材料传输方式最近引起了人们的广泛关注。到目前为止，研究主要集中在溶液中离散结构的传输，例如胶体颗粒、蛋白质和聚合物。然而，膜和凝胶等软连续结构对温度梯度的响应在很大程度上尚未被探索。在这里，我们研究了由堆叠的表面活性剂双层膜制成的层状相在温度梯度下的行为。我们发现膜向低温区域迁移，导致膜向该方向波动程度增加。这与我们的直觉相反，即温度较低时波动较弱。我们表明，这可以通过在来自每个膜的连通性的拓扑约束下温度梯度引起的膜迁移来解释。我们还揭示了楔形单元中形成的刃位错阵列的图案可以通过温度梯度控制。这些发现表明，温度梯度的应用提供了一种新的方法来控制软连续结构（例如膜、凝胶和泡沫）的组织，其方式与其他类型的场本质上不同，并可以操纵拓扑缺陷。
Thermophoresis, which is mass transport induced by a temperature gradient, has recently attracted considerable attention as a new way to transport materials. So far the study has been focused on the transport of discrete structures such as colloidal particles, proteins, and polymers in solutions. However, the response of soft continuous structures such as membranes and gels to a temperature gradient has been largely unexplored. Here we study the behavior of a lamellar phase made of stacked surfactant bilayer membranes under a temperature gradient. We find the migration of membranes towards a low-temperature region, causing the increase in the degree of membrane undulation fluctuations towards that direction. This is contrary to our intuition that the fluctuations are weaker at a lower temperature. We show that this can be explained by temperature-gradient-induced migration of membranes under the topological constraint coming from the connectivity of each membrane. We also reveal that the pattern of an edge dislocation array formed in a wedge-shaped cell can be controlled by a temperature gradient. These findings suggest that application of a temperature gradient provides a novel way to control the organization of soft continuous structures such as membranes, gels, and foams, in a manner essentially different from the other types of fields, and to manipulate topological defects.