Boateng Linkel K, Madarshahian Ramin, Yoon Yeomin, Caicedo Juan M, Flora Joseph R V
Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC, 29634, USA.
Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC, 29208, USA.
J Mol Model. 2016 Aug;22(8):185. doi: 10.1007/s00894-016-3049-2. Epub 2016 Jul 21.
A probabilistic approach is proposed to estimate water permeability in a cellulose triacetate (CTA) membrane. Water transport across the membrane is simulated in reverse osmosis mode by means of non-equilibrium molecular dynamics (MD) simulations. Different membrane configurations obtained by an annealing MD simulation are considered and simulation results are analyzed by using a hierarchical Bayesian model to obtain the permeability of the different membranes. The estimated membrane permeability is used to predict full-scale water flux by means of a process-level Monte Carlo simulation. Based on the results, the parameters of the model are observed to converge within 5-ns total simulation time. The results also indicate that the use of unique structural configurations in MD simulations is essential to capture realistic membrane properties at the molecular scale. Furthermore, the predicted full-scale water flux based on the estimated permeability is within the same order of magnitude of bench-scale experimental measurement of 1.72×10(-5) m/s.
提出了一种概率方法来估计三醋酸纤维素（CTA）膜的水渗透性。通过非平衡分子动力学（MD）模拟，在反渗透模式下模拟水在膜中的传输。考虑了通过退火MD模拟获得的不同膜构型，并使用分层贝叶斯模型分析模拟结果，以获得不同膜的渗透率。通过过程级蒙特卡罗模拟，利用估计的膜渗透率来预测全尺寸水通量。基于结果，观察到模型参数在总模拟时间5纳秒内收敛。结果还表明，在MD模拟中使用独特的结构构型对于在分子尺度上捕捉实际的膜特性至关重要。此外，基于估计渗透率预测的全尺寸水通量与台架规模实验测量的1.72×10(-5) m/s处于同一数量级。
