Naskar Supriyo, Sahoo Anil Kumar, Moid Mohd, Maiti Prabal K
Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.
Max Planck Institute of Colloids and Interfaces, Am Muhlenberg 1, 14476 Potsdam, Germany.
Phys Chem Chem Phys. 2022 May 11;24(18):11196-11205. doi: 10.1039/d1cp04557a.
Nanopore desalination technology hinges on high water-permeable membranes which, at the same time, block ions efficiently. In this study, we consider a recently synthesized [, 151-155 (2019)] phenine nanotube (PNT) for water desalination applications. Using both equilibrium and non-equilibrium molecular dynamics simulations, we show that the PNT membrane completely rejects salts, but permeates water at a rate which is an order-of-magnitude higher than that of all the membranes used for water filtration. We provide the microscopic mechanisms of salt rejection and fast water-transport by calculating the free-energy landscapes and electrostatic potential profiles. A collective diffusion model accurately predicts the water permeability obtained from the simulations over a wide range of pressure gradients. We propose a method to calculate the osmotic water permeability from the equilibrium simulation data and find that it is very high for the PNT membrane. These remarkable properties of PNT can be applied in various nanofluidic applications, such as ion-selective channels, ionic transistors, sensing, molecular sieving, and blue energy harvesting.
纳米孔脱盐技术依赖于高透水性的膜，这种膜同时能高效地阻挡离子。在本研究中，我们考虑一种最近合成的（[，151 - 155 (2019)]）菲宁纳米管（PNT）用于水脱盐应用。通过平衡和非平衡分子动力学模拟，我们表明PNT膜能完全拒盐，但透水速率比所有用于水过滤的膜高出一个数量级。我们通过计算自由能景观和静电势分布来提供拒盐和快速水传输的微观机制。一个集体扩散模型能准确预测在广泛压力梯度范围内模拟得到的水渗透率。我们提出一种从平衡模拟数据计算渗透水渗透率的方法，并发现PNT膜的该渗透率非常高。PNT的这些显著特性可应用于各种纳米流体应用，如离子选择性通道、离子晶体管、传感、分子筛分和蓝色能源收集。
