Collaborative Research: EAGER: A Proof of Concept Study to Demonstrate Tunable Thermal Rectification in Liquids

CBET-1246536/1246611 Murad/Puri热整流允许材料根据热传递的方向同时表现为导体和绝缘体。 对于表现出热整流的材料来说，它不可能是均匀的，并且它的热导率应该取决于材料中的局部温度和位置。这一要求通常导致这样的结论，即只有复合材料，如分层墙，将表现出热整流。我们提出了一个概念研究证明，热整流可以诱导液体，一般是均匀的，否则被认为是合适的。这将通过使用通过施加的电场或磁场的外力或通过引入表面力（例如，通过使表面疏水或亲水）来操纵固体-流体界面来示出。我们将使用分子动力学的方法，使用我们已经开发的技术来研究在这样的固体-流体界面的热传递和由此产生的热整流。 因此，我们希望证明热整流的可能性，为广泛的液体，已经被认为是适合于工业应用。热整流在电子和热电设备的热管理有重要的应用。它还有助于改善可持续性解决方案，例如现在越来越多地使用太阳能热水器，其中不希望在夜间释放热量。 其他可能的应用包括生物医学超声设备，热计算机，节能和收集材料，以及方向相关的绝缘材料。 固体不能容易地操纵，因此难以调谐，即，改变他们的整改行为液体更容易接受这样的调整，这将使整流能够动态地改变。因此，材料可以在需要时表现出整流;否则整流的方向性可以被颠倒，甚至完全关闭。这将使许多新的设备受益于热整流比目前可能的。

CBET-1246536/1246611Murad/Puri Thermal rectification permits a material to behave both as a conductor and an insulator simultaneously depending on the direction of heat transfer. For a material to exhibit thermal rectification it cannot be homogeneous, and its thermal conductivity should be dependent both on the local temperature in the material and the location. This requirement has generally led to the conclusion that only composite materials, such as layered walls, will exhibit thermal rectification. We propose a proof of concept study to demonstrate that thermal rectification can be induced in liquids that are generally homogeneous and not otherwise considered suitable. This will be shown by manipulating solid-fluid interfaces using either external forces through applied electric or magnetic fields, or by introducing surface forces, e.g. by rendering the surfaces hydrophobic or hydrophilic. We will use the method of molecular dynamics using a technique we have developed to investigate heat transfer at such solid-fluid interfaces and the resulting thermal rectification. We thus hope to demonstrate the possibility of thermal rectification for a wide range of liquids that are already deemed suitable for industrial applications.Thermal rectification has important applications in the thermal management of electronics and thermoelectric devices. It can also contribute to improving sustainability solutions, such as solar water heaters that are now being increasingly used, where it is undesirable to loose heat at night. Other possible applications include biomedical ultrasound devices, thermal computers, energy saving and harvesting materials, and direction dependent insulating materials. Solids cannot be easily manipulated so it is difficult to tune, i.e., change, their rectification behavior. Liquids are more amenable to such tuning, which will enable the rectification to be dynamically changed. Thus a material could exhibit rectification when desirable; else the directionality of rectification could be inverted or even tuned off completely. This would allow many new devices to benefit from thermal rectification than is currently possible.