Understanding PEM Structure and Properties

Unraveling relations among structure, physical properties, and performance of PEMs is a hierarchical challenge, as reflected in Equation 2.1. It evolves around the versatile role of water as pore former, pore filler, proton solvent, and proton shutde. The two key challenges for in-depth studies of membrane materials are 

Assuming that the size and shapes of water-filled domains are known, as well as the structure of polymer/water interfaces, proton distributions at the microscopic scale can be studied with molecular dynamics simulations (Feng and Voth, 2011 Kreuer et al., 2004 Petersen et al., 2005 Seeliger et al., 2005 Spohr, 2004 Spohr et al., 2002) or using the classical electrostatic theory of ions in electrolyte-filled pores with charged walls (Commer et al., 2002 Eikerling and Komyshev, 2001). An advanced understanding of spatial variations of proton mobility in pores warrants quantum mechanical simulations. 

---