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Grazing Incidence Wide-Angle X-ray Scattering of Water Adsorption in Polyamide Barrier Layers of Reverse Osmosis Membranes

Journal Article · · Macromolecules
 [1];  [1];  [1];  [2];  [2];  [3];  [1]
  1. Stony Brook Univ., NY (United States)
  2. Univ. of South Carolina, Columbia, SC (United States)
  3. Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
To understand the relationship between the intermolecular structure of aromatic polyamide (PA) scaffold and the water molecules in the barrier layers of reverse osmosis (RO) membranes, a grazing incidence wide-angle X-ray scattering (GIWAXS) study was carried out on freestanding PA thin films at varying relative humidity (RH) conditions. The scattering results were analyzed by an interference scattering model, containing a phase factor between a PA chain and an adsorbed water molecule. This model yielded good fits to the GIWAXS profiles where the water adsorption was found to vary linearly with RH. Atomistic molecular dynamics (MD) simulations were also performed to complement the experimental study. Furthermore, the simulations revealed that a rapid condensation layer initially formed on the PA film surface, followed by the slow water molecule diffusion inside the PA membrane. Sparse adsorbed water, isolated in subnanopores of the PA film adjacent to the polar atoms, even in very low quantities, modifies the X-ray scattering. Atomistic simulations at the microscopic scale provide partial support for several X-ray scattering findings.
Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
Grant/Contract Number:
SC0012704
OSTI ID:
2587802
Report Number(s):
BNL--228873-2025-JAAM
Journal Information:
Macromolecules, Journal Name: Macromolecules Journal Issue: 1 Vol. 58; ISSN 1520-5835; ISSN 0024-9297
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English

References (42)

Details of surface features in aromatic polyamide reverse osmosis membranes characterized by scanning electron and atomic force microscopy journal July 1999
Light scattering and capillary condensation in porous media journal March 1977
A new thin-film composite seawater reverse osmosis membrane journal January 1980
Surface modification of commercial composite polyamide reverse osmosis membranes journal February 1998
Water vapour adsorption in highly porous carbons as seen by small and wide angle X-ray scattering journal April 2010
PXLink: A simulation program of polymer crosslinking to study of polyamide membrane journal October 2023
A recent progress in thin film composite membrane: A review journal February 2012
Probing the hydrophobicity of commercial reverse osmosis membranes produced by interfacial polymerization using contact angle, XPS, FTIR, FE-SEM and AFM journal September 2011
Seawater Reverse Osmosis (SWRO) desalination by thin-film composite membrane—Current development, challenges and future prospects journal February 2012
Thin film composite membrane — Recent development and future potential journal January 2015
Synchrotron SAXS to probe cross-linked network of polyamide ‘reverse osmosis’ and ‘nanofiltration’ membranes journal December 2012
The porous structure of the fully-aromatic polyamide film in reverse osmosis membranes journal February 2015
Probing the internal structure of reverse osmosis membranes by positron annihilation spectroscopy: Gaining more insight into the transport of water and small solutes journal July 2015
Hydration of a polyamide reverse-osmosis membrane journal March 2016
Rejection mechanisms for contaminants in polyamide reverse osmosis membranes journal July 2016
Molecular simulations of polyamide membrane materials used in desalination and water reuse applications: Recent developments and future prospects journal February 2017
Transport of small and neutral solutes through reverse osmosis membranes: Role of skin layer conformation of the polyamide film journal May 2018
Morphology and porous structure of standalone aromatic polyamide films as used in RO membranes – An exploration with SANS, PALS, and SEM journal March 2019
Impact and progress in small and wide angle X-ray scattering (SAXS and WAXS) journal October 2013
Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer journal September 2013
GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers journal September 2015
Aromatic Polyamide Reverse-Osmosis Membrane: An Atomistic Molecular Dynamics Simulation journal September 2016
Atomistic Simulations of Biofouling and Molecular Transfer of a Cross-linked Aromatic Polyamide Membrane for Desalination journal May 2020
Self-Assembled Monolayers of an Azobenzene Derivative on Silica and Their Interactions with Lysozyme journal December 2015
Quantifying Carboxylic Acid Concentration in Model Polyamide Desalination Membranes via Fourier Transform Infrared Spectroscopy journal August 2018
Molecular Structure of Aromatic Reverse Osmosis Polyamide Barrier Layers journal March 2019
Evolution of Composite Reverse Osmosis Membranes book December 1985
Small-Angle X-ray Scattering of Polymers journal June 2001
Optimization of the Additive CHARMM All-Atom Protein Force Field Targeting Improved Sampling of the Backbone ϕ, ψ and Side-Chain χ 1 and χ 2 Dihedral Angles journal August 2012
Strong Surface Hydration and Salt Resistant Mechanism of a New Nonfouling Zwitterionic Polymer Based on Protein Stabilizer TMAO journal September 2021
Kinetics of Film Formation by Interfacial Polycondensation journal March 2005
CHARMM36m: an improved force field for folded and intrinsically disordered proteins journal November 2016
Multimodal confined water dynamics in reverse osmosis polyamide membranes journal May 2022
Canonical sampling through velocity rescaling journal January 2007
Particle mesh Ewald: An N ⋅log( N ) method for Ewald sums in large systems journal June 1993
An automated spin-assisted approach for molecular layer-by-layer assembly of crosslinked polymer thin films journal November 2012
X-ray Scattering Studies of Reverse Osmosis Materials journal August 2020
X-ray scattering factors computed from numerical Hartree–Fock wave functions journal March 1968
Water transport in reverse osmosis membranes is governed by pore flow, not a solution-diffusion mechanism journal April 2023
Sub-10 nm polyamide nanofilms with ultrafast solvent transport for molecular separation journal June 2015
3D printed polyamide membranes for desalination journal August 2018
Polymeric structures at interfaces: An X-ray scattering study journal April 2004

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