Shape Optimization of Nanopores by Dissolutive Flow

Abstract

Nanopores are ubiquitous across disciplines, ranging from bioscience to energy science. Enhancing their transport properties and energy storage capability is crucial to improving functionality. Dissolutive flow, which involves the removal of geometrical obstructions, can transform solid structures into shapes that are less obstructive. In this study, we utilized molecular dynamics simulations to optimize the shape of nanopores through a dissolution-based approach, resulting in optimized inlet and outlet configurations. Furthermore, we examined the distribution of pressure and stress to elucidate the mechanisms underlying shape evolution and edge effects. Conventional inlets impede liquid flow due to high pressure at the apex, a phenomenon we refer to as the reservoir pattern. As dissolution progresses, the apex pressure is significantly reduced over time, allowing a transition to the sliding pattern. By manipulating the dissolubility, wall velocity, and nanopore length, the optimized shape can be fine-tuned. Experiments conducted at the microscale confirmed the emergence of analogous optimized shapes. Additionally, we investigated the transport properties and energy storage capability of various nanopores using molecular dynamics simulations, demonstrating that the optimized nanopore can significantly reduce the hydrodynamic resistance and accelerate the charging rate. This research offers theoretical insights into nanopore dissolution and presents a viable strategy for the practical fabrication of optimized nanopores.