Effects on Nafion® 117 Membrane using Different Strong Acids in Various Concentrations

Abstract

The effects of the acid nature and its concentration on the physico chemical properties of the membranes were studied. How these parameters impact the performance of Nafion 117 as a polymer Electrolyte membrane is shown.In particular the effect of this membrane treatment on its properties was studied with the following five strong acids: -Nitric, Sulphuric, Perchloric, Phosphoric or Hydrochloric acid- in six different concentrations: -0.025 M, 0.05 M, 0.25 M, 0.5 M, 0.75 M and 1 M.It was found that the membrane shows a similar behaviour when it is treated with different strong acids, incorporating between 16 to 21 molecules of water depending on the concentration of the acid. The results show that the effect of the different concentrations on the membrane behaviour is remarkable. This leads to the conclusion that the best treatment is to use solutions 0.025 M and 0.05 M (twenty times more diluted than the most concentrated solution tested in the experience) of the strong acid.It was also shown that after the membrane hydration its size increases by 10 percent (average).