基于单离子径迹纳米核孔的离子液体导电机制研究

By irradiation of the high energy heavy ions on a polymer foil, the energetic ions can pass through the foil forming a single or multiple latent tracks on it. With breaking of chemical bond/structures, the chemical etching speed along the latent track is much faster than the speed of substrate materials, enabling to fabricate a one-dimensional nanopore, which now has become one of the most important platforms for studying the nanofluidic phenomena. .The Room Temperature Ionic Liquids (RTIL) are the (usually organic) salts in liquid state at room temperature, which have many unique physiochemical properties and wide applications, such as ionic (conductive) gels, super-capacitor, electrochemical catalysis, solar thermos energy, batteries and so on. Many of the applications were based on the properties of ions in nano-porous materials. However, the packaging of the organic ions and mechanisms of ions transport in nanoscale are still not clear, which can be changed by many factors - pore/channel geometry, surface properties and state of ionic liquids. .The ion track nanopore is an excellent option to study the ionic transport in nano-confined space due to the well-defined geometry and well-controlled surface properties. Hereby, we propose to use the single ion track etched nanopore to study the mass (ion) transport within the nanofluidic system. With well controlled physical properties of pore size and surface properties (from negatively charged to positively charged), we could study the ionic conduction within few nanometer size pores, thus derive its related phase transitions in the nanopore. By verifying the surface charge at the inner wall surface of the nanopore, we could study the ionic conductance under different ions packaging (layering effects). Finally, we could conclude the transport phenomena and use the theoretical modeling, including Finite Element Analysis and Molecular Dynamic simulations, to deeply understand the ionic transport mechanisms within the nanopore. This has meanings to explore new phenomena and optimize the ionic liquids nanofluidic devices.

利用离子核径迹技术制备的单纳米孔，在纳米流体理论与应用等方面的研究是广受关注的热点，其已成为研究纳米尺度限域空间中物质传输的重要工具。而离子液体由于其独特的物理化学性质，被广泛应用于各类化学及新材料研究，如在纳米介孔材料中可制备离子液体凝胶，超级电容等。然而离子液体在纳米孔隙中传输性质和物理机制仍有待进一步研究。核径迹纳米单孔具有孔径及界面性质可控、形貌多样等优势，为研究离子液体在限域空间中的传输问题创造了天然的有利条件。本项目利用核径迹纳米单孔系统地研究离子液体在限域空间中的电学传输现象，总结规律并建立相应理论模型。拟从物理空间尺寸、界面与离子相互作用、分子构型变化三个方面开展对电导率、电流调制等效应的研究。通过本研究，掌握离子液体在纳米限域空间中的电导现象，探明各个关键物理参数对其传输机制的影响，为拓展基于离子液体的纳米流体器件及相关应用提供理论基础。

利用离子核径迹技术制备的单纳米孔，在纳米流体理论与应用等方面的研究是广受关注的热点，其已成为研究纳米尺度限域空间中物质传输的重要工具。然而离子液体在纳米孔隙中传输性质和物理机制仍有待进一步研究。本项目通过以下几个方面对纳米尺度的离子传输现象和机制进行了研究：首先，成功利用合作单位中科院重近代物理研究所的重离子加速器制备核径迹纳米单孔及多孔。其次，研究了物理尺寸效应对离子传输的影响，如孔道端口效应对离子传输和化学检测传感的应用；离子与界面相互作用下的滑移长度研究，颠覆了传统带电荷特性对滑移长度的认识；各向异性纳米通道的构筑，研究了其物理尺寸和界面相互作用等条件影响下的离子传输规律，并通过器件集成等探究了基于浸润性变化原理的生化检测；智能界面修饰构造了温度调控的离子传输基于核径迹孔道的纳米流体器件。通过实验研究，探明离子液体与水的混合物在纳米尺度的传输的规律，以及与宏观规律的明显区别。第三，利用孔道能够产生流动和收集电能，创造了近80%的能量转换效率。培养研究生（含联合培养）5人获得硕士学位，发表国际期刊论文10篇，其中包含Nature Communications，PRL等知名期刊论文，获得国家发明专利授权2项，国际PCT专利1项。