Partition–diffusion–reaction bounds for thin-film membrane formation kinetics
Name
Deshmukh_ConcFieldReactRate_2025Aug15_Video.mp4
Description
Supplemental video of concentration field changing in time
Size
6.1 MB
Format
Video Quicktime
Checksum (MD5)
0dd9e30d5a97371865d8ca4da8e0061f
Name
Deshmukh_PDR_Mem_2025Dec07_CombPreprint.pdf
Size
3.45 MB
Format
Adobe PDF
Checksum (MD5)
dc04479f5bd5489c880f85d168ef112f
Author(s)
Deshmukh, Akshay
Elimelech, Menachem
Lienhard, John H.
Date Issued
November 15, 2025
Journal
Chemical Engineering Journal
Publisher
Elsevier BV
Citation
Deshmukh, Akshay, Elimelech, Menachem and Lienhard, John H. 2025. "Partition–diffusion–reaction bounds for thin-film membrane formation kinetics." Chemical Engineering Journal, 524.
Version
Author's final manuscript
Abstract
New membrane chemistries and structures have rapidly developed over the last ten
years, driven by applications ranging from critical metals separations and carbon capture to highly chlorine-resistant reverse-osmosis membranes. The thin selective layer
at the heart of reverse osmosis and nanofiltration membranes is typically fabricated using interfacial synthesis, with multifunctional aqueous-phase monomers and organicphase monomers. Here, we develop a physics-based model of partition, diffusion, and
reaction dynamics during the early stages of interfacial synthesis. These processes
critically impact membrane structure and performance. By solving the resulting partial
differential equations numerically and with analytical approximations, we demonstrate
that the planar reaction rate is initially limited by the partitioning and diffusion of the
aqueous-phase reactant into the organic phase. Later, finite reactant availability and
aqueous-phase diffusion become limiting. Through a combination of nondimensionalization, parameter mapping, and property prediction, we develop a framework that
spans a wide parameter space in reactant chemistry, solvent and support layer choice,
and initial reactant concentrations. We demonstrate that the planar reaction rate and
dynamics are strongly affected by the partition coefficient of the aqueous reactant,
which varies rapidly with changes in reactant and solvent chemistry. The influence
of diffusion variations is more limited. This tractable, physics-based model enables
the rapid quantification of monomer and solvent impact on interfacial synthesis, which
is essential for the rational development of new high-performance thin-film composite
membranes.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Creative Commons Attribution-Noncommercial-ShareAlike
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DOI of Published Version
https://doi.org/10.1016/j.cej.2025.169670
