Direct measurement of nanofluxes and structural relaxations of perfluorinated ionomer membranes by scanning probe microscopy
نویسندگان
چکیده
This nanorheological study addresses the water transport hindrance in perfluorinated ionomer membranes (Nafion® H+ form) in conjunction with structural relaxation properties of the polymer matrix. A low-temperature relaxation of the “dry” Nafion® matrix at 79 ◦C, about 35 ◦C below the glass transition temperature, was found to be responsible for a steady improvement of the water transport above 70 ◦C. The low-temperature structural transition at 79 ◦C was observed for the dehydrated membrane, and thus, is specific to the polymer matrix and not a sole consequence o p ( d m ©
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