基于AFM胶体探针技术的表面电荷测量与调制研究

Converting mechanical energy to electrical energy can be achieved by transporting net charges in electric double layer by pressure driven flow in nanofluidics. This is a novel technique to develop green energy device, and modulating surface charge on the solid-liquid interface can essentially enhance the energy conversion efficiency. In this proposal, we plan to set up AFM colloidal probe technique, in order to obtain the surface charge density in the electric double layer directly, and to measure the change of surface charge density on the wall insulating layer under external electric field. The influence of insulating layer material, ion concentration in solution and pH on the surface charge modulation will be studied experimentally. To further examine the modulation effect, we will also use pico-amperemeter to measure the streaming current in micro/nanochannel with wall insulating layer. Theoretically, we are going to study the mechanism of surface charge modulation with reference to the theory of charge regulation. This proposal will contribute to the clarification of the mechanism of enhancing nanofluidic energy conversion by modulating surface charge, and provide the reliable results for the design of nanofluidic energy conversion devices.

在纳流控中通过压力定向输运双电层中的净电荷可以实现机械能向电能的转换。这提供了一种发展新型清洁能源器件的技术，而调制液固界面处的表面电荷可以有效地提高能量转换效率。本申请拟采用AFM胶体探针技术直接测量双电层内的表面电荷密度，并测量外加电场对壁面绝缘层表面电荷密度调制的改变量。实验中将研究壁面绝缘层材料的属性、溶液离子浓度和pH值等对表面电荷密度调制的影响。为了进一步定量考察能量转换的效果，还将使用皮安电流计测量带绝缘层壁面的微/纳米流道中的流向电流。理论方面，本申请拟通过电荷调节理论研究表面电荷调制的机理。上述研究将有助于阐明纳流控中利用调节表面电荷增强能量转换的机理，并为能量转换器件的设计提供可靠依据。

在纳流控中通过压力定向输运双电层中的净电荷可以实现机械能向电能的转换。这提供了一种发展新型清洁能源器件的技术，而调制液固界面处的表面电荷可以有效地提高能量转换效率。本研究系统的研究了通过极化外电场调制绝缘层表面电荷密度。理论方面，通过电荷调节理论研究表面电荷调制的机理，建立了可靠的物理模型给出数值解。实验上采用AFM胶体探针技术直接测量双电层内的表面电荷密度，并测量外加电场对壁面绝缘层表面电荷密度调制的改变量。实验中研究了壁面绝缘层材料的属性、溶液离子浓度和pH值等对表面电荷密度调制的影响。为进一步定量考察能量转换的效果，还使用皮安电流计测量带绝缘层壁面的微/纳米流道中的流向电流。上述研究有助于阐明纳流控中利用调节表面电荷增强能量转换的机理，并为能量转换器件的设计提供可靠依据。