63158 event 1292326078 1475891616 <![CDATA[Giuseppe Brunello - PhD Proposal Defense]]> Abstract:  Polymer Electrolyte Membrane Fuel Cells (PEMFC) are one of the most promising fuel cell technologies to someday supplant the internal combustion engine in transportation; however, several material shortcomings limit their adoption, except for niche applications. The polymer chosen largely determines the features of the fuel cell such as the current capacity, the type of fuels, the water management strategy and the operating temperature. Particularly, the operating temperature and the water management are related to each other via the nanophase-segregated structure of the membrane, and furthermore, the operating temperature influences the reactivity and stability of catalyst at the catalyst layer and the transport properties through the membrane.  

 

 In this research, first, a comprehensive understanding of the fundamental molecular mechanisms will be pursued by characterizing the membrane materials using molecular dynamics (MD). MD investigates the polymer materials at the atomic level, with the aim to obtain an understanding of the molecular level reasons for the thermodynamic properties and transport mechanisms of these membranes. An understanding of how the structure and size of the clusters affect their stability and their dissolution mechanism is sought for the catalysts by studying their quantum mechanical properties. The appropriate tool for this is density functional theory (DFT). Using the understanding obtained for the membrane and catalyst, an MD model of the three phase interface region will be developed to understand how the various materials interact and affect each other.

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