Diverse ionic current rectification methods for nanofluidic chips have recently emerged. Herein, we theoretically demonstrate that by applying a temperature gradient to the aqueous solution, the ionic rectification property of a tapered nanochannel can be manipulated by applying temperature gradients from the tip to base and vice versa. Our modeling results reveal that the rectification ratio can be significantly enhanced by applying a temperature increment from the base to tip, whereas the rectification ratio is significantly suppressed by applying a reverse temperature gradient. In addition to the solution temperature, we also investigated the influence of bulk ionic strength and tip height on the rectification ratio, thereby providing overlapping and non-overlapping regimes of electrical double layers. We demonstrate that the rectification behavior of a tapered nanochannel is determined by the overlapping regime of the electrical double layer at the tip of the nanochannel. Moreover, we propose a semi-analytical solution that can capture numerical results with the same order of magnitude. We expect that the modeling results of this contribution can provide a direction for understanding ionic transport across geometrically and thermally asymmetrical media, which could find applications from energy conversion to logical nanofluidic chip components.

最近出现了用于纳米流体芯片的各种离子电流整流方法。在这里，我们从理论上证明，通过对水溶液施加温度梯度，可以通过从尖端到底部施加温度梯度来操纵锥形纳米通道的离子整流特性，反之亦然。我们的建模结果表明，通过从底部到尖端施加温度增量，可以显着提高整流比，而通过应用反向温度梯度，可以显着抑制整流比。除了溶液温度，我们还研究了体离子强度和尖端高度对整流比的影响，从而提供了双电层的重叠和非重叠状态。我们证明了锥形纳米通道的整流行为是由纳米通道尖端双电层的重叠方式决定的。此外，我们提出了一种半解析解，可以捕获相同数量级的数值结果。我们期望这一贡献的建模结果可以为理解跨几何和热不对称介质的离子传输提供一个方向，这可以找到从能量转换到逻辑纳米流体芯片组件的应用。