Abstract Asymmetric membranes and asymmetric pores are broad classes of objects, the role of which is steadily growing in academia and industry. During the last two decades, asymmetric (often called “conical”) track-etched nanopores have attracted increasing attention from the scientific community due to their great potential for accomplishing useful functions in nanofluidic devices. A great body of knowledge has been gained on the electrical and electroosmotic properties of track-etched asymmetric nanopores in electrolyte solutions. Less attention has been paid to the pore geometry, and practically no attempts have been made to explore their osmotic and hydraulic properties. The present study fills this gap by examining the interrelations between the electrical, osmotic, hydraulic and structural characteristics of an asymmetrically etched ion-track nanopore. Several consecutive phases of pore evolution are identified. In the last phase, the highly asymmetric membrane resembles a porous 2D material. The temporal dependences of the two counter-fluxes – the diffusional flux of the etchant and the volume flux of stopping media - are elucidated and analyzed in light of their effect on the nanopore configuration. The osmotic reflection coefficients of highly asymmetric pores are estimated under etching conditions and in diluted electrolyte solutions. Our results allow a new level of understanding of the phenomena underlying the development of an ion-track nanopore and pave the way for the controlled fabrication of a variety of nanopores of different shapes using one and the same principle of an asymmetric chemical treatment.

中文翻译：

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阐明扩散和渗透流在控制非对称径迹蚀刻膜中纳米通道几何形状中的作用

摘要 非对称膜和非对称孔是一大类物体，其在学术界和工业界的作用正在稳步增长。在过去的二十年中，不对称（通常称为“锥形”）径迹蚀刻纳米孔由于其在纳米流体装置中实现有用功能的巨大潜力而​​引起了科学界越来越多的关注。关于电解质溶液中径迹蚀刻的不对称纳米孔的电和电渗性质，已经获得了大量知识。对孔隙几何形状的关注较少，实际上也没有尝试探索它们的渗透和水力特性。本研究通过检查电、渗透、不对称蚀刻离子轨道纳米孔的水力和结构特征。确定了孔隙演化的几个连续阶段。在最后阶段，高度不对称的膜类似于多孔二维材料。根据它们对纳米孔配置的影响，阐明和分析了两种反向通量的时间依赖性 - 蚀刻剂的扩散通量和停止介质的体积通量。高度不对称孔的渗透反射系数在蚀刻条件和稀释的电解质溶液中进行估计。