Abstract A concept of the porous graphene membrane centrifuge is proposed aiming at fabrication of large scale, fouling-free desalination machine with nanomaterial-based reverse osmosis modules. The concept as well as strategy of such porous rotating graphene membrane device is approved through molecular dynamics (MD) modeling and simulation of a nano-fluidic device that in order to make a quantitative evaluation. First, an analytical formulation is derived for the critical angular velocity above which the centrifugal force is able to counter-balance osmosis pressure, so that the reverse osmosis (RO) desalination process can proceed. The critical angular velocity derived from this formulation is compared with MD simulated critical angular velocity. Based on MD simulation results, it is shown that the rotating porous membrane device may significantly improve desalination efficiency by combining the centrifugal separation and and the selectivity of porous graphene membrane to achieve reverse-osmosis desalination. Furthermore, we have shown that the proposed desalination device has an intrinsic anti-fouling mechanism, and then we have studied the effect of pore size on the flux rate by conducting simulations with the applied rotating speed. Moreover, we have conducted energy and efficiency analysis for the proposed desalination device model, and we obtained the relationship between fresh water flux rate and the angular velocity, at the same time, with the pore size. By choosing the most efficient angular velocity and the pore size that ensures salt rejection, an optimal nano-fluidic device design is achieved.

中文翻译：

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用于反渗透海水淡化的纳米多孔离心机的分子动力学模型

摘要 提出了多孔石墨烯膜离心机的概念，旨在制造具有纳米材料基反渗透模块的大型无污染海水淡化机。这种多孔旋转石墨烯膜装置的概念和策略通过纳米流体装置的分子动力学 (MD) 建模和模拟得到批准，以便进行定量评估。首先，推导出临界角速度的分析公式，高于该临界角速度离心力能够抵消渗透压力，从而可以进行反渗透 (RO) 脱盐过程。从该公式导出的临界角速度与 MD 模拟临界角速度进行比较。基于MD模拟结果，结果表明，旋转多孔膜装置通过结合离心分离和多孔石墨烯膜的选择性实现反渗透脱盐，可以显着提高脱盐效率。此外，我们已经证明所提出的脱盐装置具有内在的防污机制，然后我们通过对所应用的转速进行模拟来研究孔径对通量率的影响。此外，我们对提出的海水淡化装置模型进行了能量和效率分析，同时我们获得了淡水通量与角速度之间的关系，同时与孔径大小之间的关系。通过选择最有效的角速度和确保脱盐的孔径，实现了最佳的纳米流体装置设计。