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Molecular dynamics simulation of SWNT/PA thin-layer composite reverse osmosis membrane

Authors： CHEN Zhen, ZHANG Jun, LIU Xuan

Units： School of Engineering, Shanghai Ocean University, Shanghai 201306, China

KeyWords： polyamide; reverse osmosis; molecular dynamics simulation; carbon nanotube

ClassificationCode：TQ019

year,volume(issue):pagination： 2025,45(2):92-99

Abstract：

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.

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AuthorIntro：

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

Reference：

[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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