Mesoscale modeling of self-assembly and transport in polymer electrolyte membranes

Project Details

Description

TECHNICAL SUMMARY

This award supports theoretical and computational research and education to develop simulation methods to model structural and transport properties of polyelectrolyte membranes. Polyelectric membranes are one of the critical and most expensive components of the solid polymer electrolyte fuel cells, a promising technology for energy production from hydrogen and oxygen. A better understanding of the basic mechanisms of nanostructure formation and conductivity of polyelectrolyte membranes could lead to improvement of currently available solid polymer electrolyte fuel cells. Separation and transport properties of polyelectrolyte membranes are determined by their self-assembled nanostructure: upon hydration, the membrane segregates into hydrophilic and hydrophobic subphases on the mesoscopic scale. The PI aims to develop a mesoscale simulation method for studies of polyelectrolyte membranes self-assembly and proton conductivity based on the dissipative particle dynamics technique with coarse-grained interaction parameters determined from ab initio and atomistic molecular dynamics simulations. The new method includes the introduction of a mesoscopic model of proton transport along the hydrophilic subphase of the self-assembled polyelectrolyte membranes. The new method will be tested against available experimental data and earlier simulations of ionomer fragments and traditional Nafion membranes.

The simulation method will enable direct computational investigation of segregated morphology and proton transport in coupled polyelectrolyte membranes. The PI aims to advance fundamental understanding of the physico-chemical mechanisms of self-assembly, water sorption and permeability, and proton conductivity. The simulation methods that will be developed and structure-property relationships that will be established have the potential to have significant impact and accelerate the search of new polyelectrolytes for permselective membranes for fuel cells, thus contributing to the effort to develop novel materials for sustainable hydrogen-based energy technologies.

This award supports graduate, undergraduate, and postdoctoral training in theoretical and computational nanomaterials science and engineering. Minority undergraduate students will be recruited through the Rutgers special training programs. A dedicated webpage will be created for making project reports and presentations available for educational purposes. Computor codes together with instructive case study examples will be posted on this webpage for free distribution to the scientific community. Simulation methods developed and case-study systems will be included into a new graduate course on 'Nanoscale Thermodynamics and Transport.'

NONTECHNICAL SUMMARY.

This award supports theoretical research and education to develop computational methods for modeling structural and transport properties of polyelectrolyte membranes. Polyelectrolyte membranes are one of the critical and most expensive components of polymer exchange membrane fuel cells, a promising technology for the extraction of electric energy from hydrogen and oxygen. Polyelectrolyte membranes are made of complex chain molecules composed of hydrophobic and hydrophilic fragments. To function in a fuel cell, a polyelectrolyte membrane separates the two electrodes, the anode and the cathode, and allows only hydrogen ions or protons to pass through it leaving electrons behind. Hydrogen atoms, composed of a proton and an electron, are split at the anode liberating the electron that flows to the cathode through an electric circuit, for example the motor in an electric car. The proton flows through membrane to the cathode where it is reunited with the electron that has traveled trhough the circuit and oxygen atoms to form water which is expelled from the fuel cell. The ability of the polyelectrolyte membrane to conduct only protons is crucial for the operation of the fuel cell. Under working conditions, polyelectrolyte membranes exhibit a kind of self-assembly or restructuing of its molecules - the hydrophobic fragments form a three dimensional network of proton-conducting channels. The ability of the membrane to conduct protons depends of the specifics of the chemical composition and structure of the membrane that results from the self-assembly process. The PI will develop a novel computer simulation technique to determine the relationships among the chemical composition of the polyelectrolyte membrane, its structure under working conditions, and its ability to conduct protons, with the aim of determining optimal designs for novel fuel cell membranes.

The results of this research could have impact across disciplines, since it addresses currently unresolved topical problems related to self-assembly and charge conduction in synthetic and biological polyelectrolyte materials. Computer modeling tools developed in the course of the research can be adapted and modified for simulation and optimization of other materials with potential to have application to biomedical systems and biomedical technologies involving DNA, proteins, and physiological membranes. This research contributes to the effort to develop sustainable energy sources.

This award supports graduate, undergraduate, and postdoctoral training in theoretical and computational nanomaterials science and engineering. Minority undergraduate students will be recruited through the Rutgers special training programs. A dedicated webpage will be created for making project reports and presentations available for educational purposes. Computor codes together with instructive case study examples will be posted on this webpage for free distribution to the scientific community. Simulation methods developed and case-study systems will be included into a new graduate course on 'Nanoscale Thermodynamics and Transport.'

StatusFinished
Effective start/end date9/1/128/31/16

Funding

  • National Science Foundation: $383,803.00

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