ABSTRACT Nanoscale heat transfer between two parallel silicon slabs filled with deionized water was studied under varying electric field in heat transfer direction. Two oppositely charged electrodes were embedded into the silicon walls to create a uniform electric field perpendicular to the surface, similar to electrowetting-on-dielectric technologies. Through the electrostatic interactions, (i) surface charge altered the silicon/water interface energy and (ii) electric field created orientation polarization of water by aligning dipoles to the direction of the electric field. We found that the first mechanism can manipulate the interface thermal resistance and the later can change the thermal conductivity of water. By increasing electric field, Kapitza length substantially decreased to 1/5 of its original value due to enhanced water layering, but also the water thermal conductivity lessened slightly since water dynamics were restricted; in this range of electric field, heat transfer was doubled. With a further increase of the electric field, electro-freezing (EF) developed as the aligned water dipoles formed a crystalline structure. During EF (0.53 V/nm), water thermal conductivity increased to 1.5 times of its thermodynamic value while Kapitza did not change; but once the EF is formed, both Kapitza and conductivity remained constant with increasing electric field. Overall, the heat transfer rate increased 2.25 times at 0.53 V/nm after which it remains constant with further increase of the electric field.

中文翻译：

---

通过硅和纳米封闭水的电场控制传热

摘要 研究了在传热方向变化的电场下，两个充满去离子水的平行硅板之间的纳米级传热。两个带相反电荷的电极嵌入硅壁中，以产生垂直于表面的均匀电场，类似于电介质上的电润湿技术。通过静电相互作用，(i) 表面电荷改变了硅/水的界面能，(ii) 电场通过将偶极子与电场方向对齐而产生了水的取向极化。我们发现第一种机制可以操纵界面热阻，而后者可以改变水的热导率。通过增加电场，由于水分层增强，Kapitza 长度大大减少到其原始值的 1/5，但由于水动力受到限制，水的导热系数也略有下降；在这个电场范围内，传热增加了一倍。随着电场的进一步增加，电冷冻（EF）随着排列的水偶极子形成晶体结构而发展。在EF（0.53 V/nm）期间，水的热导率增加到其热力学值的1.5倍，而Kapitza没有变化；但是一旦形成 EF，随着电场的增加，Kapitza 和电导率都保持不变。总体而言，传热速率在 0.53 V/nm 时增加了 2.25 倍，之后随着电场的进一步增加保持不变。随着电场的进一步增加，电冷冻（EF）随着排列的水偶极子形成晶体结构而发展。在EF（0.53 V/nm）期间，水的热导率增加到其热力学值的1.5倍，而Kapitza没有变化；但是一旦形成 EF，随着电场的增加，Kapitza 和电导率都保持不变。总体而言，传热速率在 0.53 V/nm 时增加了 2.25 倍，之后随着电场的进一步增加保持不变。随着电场的进一步增加，电冷冻（EF）随着排列的水偶极子形成晶体结构而发展。在EF（0.53 V/nm）期间，水的热导率增加到其热力学值的1.5倍，而Kapitza没有变化；但是一旦形成 EF，随着电场的增加，Kapitza 和电导率都保持不变。总体而言，传热速率在 0.53 V/nm 时增加了 2.25 倍，之后随着电场的进一步增加保持不变。随着电场的增加，Kapitza 和电导率都保持不变。总体而言，传热速率在 0.53 V/nm 时增加了 2.25 倍，之后随着电场的进一步增加保持不变。随着电场的增加，Kapitza 和电导率都保持不变。总体而言，传热速率在 0.53 V/nm 时增加了 2.25 倍，之后随着电场的进一步增加保持不变。