Comparing In Situ and Ex Situ Fragmentation of Sulfonated Poly(ether ether ketone) Membranes Shulamith Schlick, University of Detroit Mercy, DMR Pinteala, M.; Schlick, S, Polym. Degrad. Stab. 2009, 94, Danilczuk, M.; Schlick, S.; Coms, F.D. Macromolecules 2013, 46, The fuel cell (FC) operation depends on the integrity of the ionomer membrane. Two approaches are used for the study of membrane stability: ex situ study of the membranes in the presence of hydroxyl radicals, and in situ study in an operating FC. For perfluorinated membranes such as Nafion, the results for the two approaches are in agreement. A different story, however, was deduced for sulfonated poly(ether ether ketone) (SPEEK) (1,2). In SPEEK exposed to the aggressive hydroxyl radicals, two spin adducts of the spin trap DMPO were detected, which are clearly a result of membrane fragmentation: DMPO/Ph and DMPO/OPh (Ph is the phenyl radical and OPh is the phenoxyl radical). However, in a FC inserted in the resonator of the ESR spectrometer, the major adducts were DMPO/H and DMPO/OOH. These results demonstrate the different stabilities of SPEEK in ex situ and in situ experiments. Conclusion: Membrane durability should be evaluated in an operating FC. Radicals detected as spin adducts Ex situ studies (ref 1): DMPO/Ph DMPO/OPh In situ studies (ref 2) DMPO/H DMPO/OOH

Broader Impact Activities Shulamith Schlick, University of Detroit Mercy, DMR The Group. Postdoctorals M. Danilczuk, and A. Bosnjakovic, undergraduate REU fellow D. Brush. Translational Research. Our collaboration with scientists and engineers from 3M, Ford Laboratories, and the Electrochemical Energy Research Lab of General Motors on the degradation and stabilization of membranes used in fuel cells is an example of the connectivity between fundamental research and applications: The kinetic approach developed by our group for ranking membrane stability and the in situ study of the mitigating Ce(III) effect have encouraged efforts on syntheses of more stable membranes and attempts to further membrane stabilization. International Collaboration. PI Schlick has continued the collaboration with the group of professor K. Kruczala (Krakow). The focus was on the thermal and chemical stability of sulfonated Parmax, a hydrocarbon membrane for FC applications: Lancucki, L.; Schlick, S.; Danilczuk, M.; Coms, F.D.; Kruczala, K. Polym. Degrad. Stab. 2013, 98, The collaboration with the 3M Fuel Cell Components Group led to a publication indicating that science corrects itself: Using FTIR, NMR, and conductivity data, we have concluded that anion exchange membranes (AEMs) generated from the fluorinated precursor of the 3M membranes are not stable (Bosnjakovic, A.; Danilczuk, M.; Schlick, S.; Haugen, G.M.; Xiong, P.N.; Hamrock, S.J. J. Membr. Sci. 2014, 467, ). This well-documented conclusion is in contrast to published literature, and is expected to save synthetic efforts and unnecessary expenses from other groups.