Cationic Membranes Produced by Swift Heavy Ions to be Applied in PEM Fuel Cells

J.E. MANZOLI; R. MAZZEI; A.B.C.GERALDO; E. MOURA; G. GARCÍA BERMÚDEZ; M.F. DEL GROSSO; V. C. CHAPPA; C. ARBEITMAN

Rio dos Angra

Simposio; 8th International Symposium on Ionizing Radiation and Polymers; 2008

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> When swift heavy ions irradiate polymers, physical and chemical changes may occur due to a very high value of the electronic stopping power.  It can lead to polymer bond breaking, free radicals, excited species, volatiles and secondary chemical processes that modify the polymer structure. The specific irradiation effects will depend strongly on parameters such as ion mass, energy, stopping power, fluence and the chemical structure of the targets.   Previous work measured the damage cross section as a function of the stopping power (dE/dx) keeping the ion velocity constant, so the track dimensions are fixed [1]. Following this idea we extended the study to other material and ion velocity.   For this purpose we irradiated High Density Polyethylene (HDPE) films with swift heavy ions: 7Li, 12C, 19F, 32S in the energy range between 21 and 96 MeV, so the selected velocity was 3 MeV/amu, greater than the 0.6 MeV/amu used by Papaleo et al.[1]. We applied Fourier Transform Infrared (FTIR) spectroscopy to measure the damage cross section for different chemical bonds, and then related it with the deposited energy density. The measurements of the irradiated samples showed similar results: an overall decrease in the intensity of the original IR bands. We will discuss the results at this new range of velocities and will analyze the dependence of the damage cross sections with the deposited energy density .