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SWNT/PA薄层复合反渗透膜的分子动力学模拟研究

作者：陈赈，张俊，刘璇

单位：上海海洋大学工程学院，上海 201306

关键词：聚酰胺；反渗透；分子动力学模拟；碳纳米管

DOI号： 10.16159/j.cnki.issn1007-8924.2025.02.011

分类号： TQ019

出版年,卷(期):页码： 2025,45(2):92-99

摘要：

采用分子动力学方法，设计了一种新型的单壁碳纳米管（SWNT）/聚酰胺（PA）薄层复合（TFC）反渗透（RO）膜结构，并建立相应模型开展复合膜水渗透系数及反渗透截盐机理研究。首先，建立PA膜模型，分析了膜厚度对水渗透系数的影响，发现水渗透系数随着膜厚度下降而增加的规律；同时，进行PA膜溶胀模拟测试，确定聚合物交联度（DPC）为83%时PA膜最为稳定。在此基础上，建立了SWNT/PA膜模型，并采用其对初始浓度为0.25 mol/L的混合盐水进行过滤测试，发现复合膜在保留高截留率的同时，水渗透系数可增至70.391 L/(m2·h·MPa)，是PA膜的1.5倍。复合膜性能的提升可归因于SWNT的掺杂不仅扩大了PA膜孔隙，而且增加了水分子传输通道。本研究从微观层面揭示了PA TFC反渗透膜的反渗透机理为尺寸筛分效应，为合理设计高性能复合反渗透膜提供了有益的理论参考。

A novel single-walled carbon nanotube (SWNT)/polyamide (PA) thin-layer composite (TFC) reverse osmosis (RO) membrane structure was designed by molecular dynamics method, and the corresponding model was established to study the water permeability coefficient of the composite membrane and the mechanism of reverse osmosis salt interception. Firstly, the PA membrane model was established, and the influence of membrane thickness on water permeability coefficient was analyzed. It was found that the water permeability coefficient increased with the decrease of membrane thickness. At the same time, the swelling simulation test of PA membrane was carried out, and it was determined that the PA membrane was the most stable when the crosslinking degree (DPC) of the polymer was 83%. On this basis, the SWNT/PA membrane model was established and used to filter the mixed brine with an initial concentration of 0.25 mol/L. It was found that the water permeability coefficient of the composite membrane could be increased to 70.391 L/(m2·h·MPa) while retaining the high rejection rate, which was 1.5 times that of the PA membrane. The improvement of the performance of the composite membrane can be attributed to the fact that the doping of SWNT not only expands the pores of the PA membrane, but also increases the water molecule transport channel. This study reveals that the salt rejection mechanism of PA TFC reverse osmosis membrane is size sieving effect from the micro level, which provides a useful theoretical reference for the rational design of high-performance composite reverse osmosis membranes.

基金项目：

作者简介：

陈赈（1999-），男，浙江金华人，硕士研究生，主要从事碳纳米管/聚酰胺薄层复合反渗透膜的分子动力学模拟研究

参考文献：

[1]Chen Q, Yang X. Pyridinic nitrogen doped nanoporous graphene as desalination membrane: Molecular simulation study[J]. J Membr Sci, 2015, 496(15): 108-117.
[2]Ding M, Ghoufi A, Szymczyk A. Molecular simulations of polyamide reverse osmosis membranes[J]. Desalination, 2014, 343(16): 48-53.
[3]赵岩雨, 张瑜, 宋向菊, 等. 中间层调控聚酰胺复合膜的研究进展[J]. 膜科学与技术, 2021, 41(6):226-235.
[4]Wang L, He J, Heiranian M, et al. Water transport in reverse osmosis membranes is governed by pore flow, not a solution-diffusion mechanism[J]. Sci Adv, 2023, 9(14): 1-12.
[5]Mansor E, Abdallah H, Shaban A M. The role of membrane filtration in wastewater treatment[J]. Environ Qual Manage, 2024, 34(1) : 1-14.
[6]Yin Y, Liu S X, Zhou J, et al. Polyamide thin film nanocomposite with in-situ co-constructed COFs for organic solvent nanofiltration[J]. J Membr Sci, 2023, 686(15): 1-13.
[7]Zhu J, Hou J, Yuan S, et al. MOF-positioned polyamide membranes with a fishnet-like structure for elevated nanofiltration performance[J]. J Mater Chem A, 2019, (7): 16313-16322.
[8]Khan N A, Yuan J Y, Wu H, et al. Covalent organic framework nanosheets as reactive fillers to fabricate free-standing polyamide membranes for efficient desalination[J]. ACS Appl Mater Interfaces, 2020, 12(24): 27777-27785.
[9]Zhang Y, Hao Z, Hussein I, et al. Tunable ionic sieving membrane via reactive layer-by-layer assembly of porous organic cages[J]. Adv Funct Mater, 2024, 34(25): 1-8.
[10]Xia M, Zhang W, Xu Y, et al. Polyamide membranes with a ZIF-8@Tannic acid core-shell nanoparticles interlayer to enhance nanofiltration performance[J]. Desalination, 2022, 541(1): 1-11.
[11]Hao W, Wang H, Li S, et al. Tailoring polyamide membranes via dynamic interfacial manipulation with functional Fe3O4 nanoparticles for elevated Nanofiltration performance[J]. Desalination, 2024, 586(1): 1-10.
[12]Matshetshe K, Sikhwivhilu K, Ndlovu G, et al. Antifouling and antibacterial β-cyclodextrin decorated graphene oxide/polyamide thin-film nanocomposite reverse osmosis membranes for desalination applications[J]. Sep Purif Technol, 2021, 278(1): 1-17.
[13]Wang G, Wu T, Zhao J, et al. Cationic COF nanosheets engineered positively charged polyamide membranes for efficient divalent cations removal[J]. J Membr Sci, 2023, 684(15): 1-9.
[14]Wang J, Yang D, Gao X, et al. Tip and inner walls modification of single-walled carbon nanotubes (3.5 nm diameter) and preparation of polyamide/modified CNT nanocomposite reverse osmosis membrane[J]. J Exp Nanosci, 2017, 13(1):11-26.
[15]Zhao H, Qiu S, Wu L, et al. Improving the performance of polyamide reverse osmosis membrane by incorporation of modified multi-walled carbon nanotubes[J]. J Membr Sci, 2014, 450（15):249-256.
[16]Li D, Li H, Wu H, et al. Using the group contribution method and molecular dynamics to predict the glass transition temperatures and mechanical properties of poly-(p-phenylenediamine-alt-2,6-diformyl multiphenyl)[J]. J Chem Res, 2021, 45(9/10) : 823-830.
[17]Ahajo B J R K, Cumpa J C D L, Lozuno A E, et al. Thermally stable polymers: Novel aromatic polyamides[J]. Adv Mater, 1995, 7(2): 148-151.
[18]Zhanga X, Cahill D G, Coronell O, et al. Absorption of water in the active layer of reverse osmosis membranes[J]. J Membr Sci, 2009, 331(1/2): 143-151.
[19]Silva T F D, Vila-Viosa S, Reis O B P S, et al. The impact of using single atomistic long-range cutoff schemes with the GROMOS 54A7 force field[J]. J Chem Theory Comput, 2018, 14(11) : 5823-5833.
[20]阮洋，李继存，陈建发. 石墨烯在线创建工具[EB/OL]. [2024]. https://jerkwin.github.io/gmxtools/model/graphene.html.
[21]Doherty B, Zhong X, Gathiaka S, et al. Revisiting OPLS force field parameters for ionic liquid simulations[J]. J Chem Theory Comput, 2017, 13(12): 6131-6145.
[22]Ma Z, Ren L, Ying D, et al. Electrospray interface-less polymerization to fabricate high-performance thin film composite polyamide membranes with controllable skin layer growth[J]. J Membr Sci, 2021, 632(5) : 1-10.
[23]Yang G, Zhang Z, Yin C, et al. Polyamide membranes enabled by covalent organic framework nanofibers for efficient reverse osmosis[J]. J Polym Sci, 2022, 60(21):2999-3008.
[24]Hu Z, Chen Y, Jiang J. Zeolitic imidazolate framework-8 as a reverse osmosis membrane for water desalination: Insight from molecular simulation[J]. J Chem Phys, 2011, 134(13): 1-7.
[25]张伟.超薄自支撑聚酰胺膜水动力学行为和截盐机理的分子动力学模拟研究[D]. 天津:天津工业大学, 2021.
[26]Abdelkader B A, Antar M A, Laoui T, et al. Development of graphene oxide-based membrane as a pretreatment for thermal seawater desalination[J]. Desalination , 2019, 465(1): 13-24.
[27]Willems T F, Rycroft C H, Kazi M, et al. Algorithms and tools for high-throughput geometry-based analysis of crystalline porous materials[J]. Micropor Mesopor Mater, 2012, 149(1):134-141.

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