Water Dynamics and Proton-Transport Mechanisms of Nafion 117/Phosphotungstic Acid Composite Membrane: A Molecular Dynamics Study

Phosphotungstic acid (HPW)-filled composite proton exchange membranes possess high proton conductivity under low relative humidity (RH). However, the leaching of HPW limits their wide application. Herein, we propose a novel approach for anchoring water soluble phosphotungstic acid (HPW) by polydopamine (PDA) coated graphene oxide and halloysite nanotubes (DGO and DHNTs) in order to construct hybrid three-dimensional proton transport networks in a sulfonated poly(ether ether ketone) (SPEEK) membrane. The introduction of PDA on the surfaces of the hybrid fillers could provide hydroxyl groups and secondary amine groups to anchor HPW, resulting in the uniform dispersion of HPW in the SPEEK matrix. The SPEEK/DGO/DHNTs/HPW (90/5/5/60) composite membrane exhibited higher water uptake and much better conductivity than the SPEEK membrane at low relative humidity. The best conductivity reached wass 0.062 S cm−1 for the composite membrane, which is quite stable during the water immersion test.

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Molecular Dynamics Simulation of Transport Mechanisms and Desalination Performance of the PSF/UiO-66 Thin-film Composite Membrane

10.21203/rs.3.rs-255737/v1 ◽

2021 ◽

Author(s):

Tianwei Mu ◽

Manhong Huang ◽

Gang Chen

Keyword(s):

Thin Film ◽

Molecular Dynamics ◽

Active Layer ◽

Composite Membrane ◽

Feed Solution ◽

Dynamics Simulation ◽

Transport Mechanisms ◽

Film Composite ◽

Salt Rejection ◽

Thin Film Composite

Abstract A novel molecular dynamics (MD) model was presented to investigate the transport mechanisms and desalination performance of a series of thin-film composite membranes. Firstly, polyamide (PA) and polysulfone (PSF), or PSF/UiO-66 was constructed by cross-linking reactions as an active layer and a support layer of the composite membrane. Subsequently, feed solution and three draw aqueous solutions with salt concentrations of 0.5, 1.0 and 1.5 M were generated by GROMACS, a molecular dynamics software that can places different solutions into separate boxes. Thirdly, these aqueous boxes and membranes were combined such that the active layer faced the feed solution or the draw solution. The forward osmosis (FO) process was then applied to anatomize the membrane fouling, water flux, and salt rejection. The results indicated that the PA-PSF/UiO-66 membrane exhibited a strong antifouling effect, high water transport and salt rejection performances compared to the pristine PA and PA-PSF membranes. This simulation work provided important insight in guiding the design and synthesis of the FO membrane.

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The Structure and Proton Transport Mechanisms in the Superprotonic Phase of CsH2PO4: An Ab Initio Molecular Dynamics Study

The Journal of Physical Chemistry C ◽

10.1021/jp800342y ◽

2008 ◽

Vol 112 (26) ◽

pp. 9917-9930 ◽

Cited By ~ 32

Author(s):

Hee-Seung Lee ◽

Mark E. Tuckerman

Keyword(s):

Molecular Dynamics ◽

Ab Initio ◽

Proton Transport ◽

Ab Initio Molecular Dynamics ◽

Transport Mechanisms ◽

Superprotonic Phase

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Characterizing and Contrasting Structural Proton Transport Mechanisms in Azole Hydrogen Bond Networks Using Ab Initio Molecular Dynamics

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.1c02266 ◽

2021 ◽

pp. 8749-8756

Author(s):

Austin O. Atsango ◽

Mark E. Tuckerman ◽

Thomas E. Markland

Keyword(s):

Molecular Dynamics ◽

Hydrogen Bond ◽

Ab Initio ◽

Proton Transport ◽

Ab Initio Molecular Dynamics ◽

Transport Mechanisms ◽

Hydrogen Bond Networks

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Proton Transport Mechanism and Pathways in the Superprotonic Phase of M3H(AO4)2 Solid Acids from Ab Initio Molecular Dynamics Simulations

Physical Chemistry Chemical Physics ◽

10.1039/d1cp00757b ◽

2021 ◽

Author(s):

Boris Merinov ◽

Sergey Morozov

Keyword(s):

Molecular Dynamics ◽

Ab Initio ◽

Proton Transport ◽

Transport Mechanism ◽

Solid Acids ◽

Ab Initio Molecular Dynamics ◽

Theoretical Studies ◽

Dynamics Simulations ◽

Experimental And Theoretical Studies ◽

Superprotonic Phase

The proton transport mechanism in superprotonic phases of solid acids is a subject of experimental and theoretical studies for a number of years. Despite this, details of the mechanism still...

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