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).

Effect of various concentration of sulfuric acid for Nafion membrane activation on the performance of fuel cell

“…The hydrogen peroxide treatment has succeeded to eliminate the organic impurities after the industrial synthesis. This is evidenced by discoloration of membrane becomes colorless as also reported by other researchers [5]. Figure 1 illustrates the relationship between the number of protons in the membrane and the concentration of sulfuric acid used in activation.…”

“…The pre-treatment to Nafion 117 membrane with strong acid, which has been developed by several researchers, intends to activate the sulfonic acid group in the membrane, by replacing other positive ions that have previously bound in the membrane with a proton from sulfuric acid [4]. Furthermore, water molecules content in the structure of membrane will increase [5]. Napoli [5] stated that many research works have explained different treatments to increase the content of water molecules in the structure of membrane.…”

“…Furthermore, water molecules content in the structure of membrane will increase [5]. Napoli [5] stated that many research works have explained different treatments to increase the content of water molecules in the structure of membrane. Based on those publication and previous studies, a specific acid treatment was performed in order to activate the membrane and increase the amount of water molecules per sulfonic group [5] Currently, sulfuric acid (H 2 SO 4 ) with concentration below 1 M is used in standard method for the activation of Nafion [6].…”

“…Napoli [5] stated that many research works have explained different treatments to increase the content of water molecules in the structure of membrane. Based on those publication and previous studies, a specific acid treatment was performed in order to activate the membrane and increase the amount of water molecules per sulfonic group [5] Currently, sulfuric acid (H 2 SO 4 ) with concentration below 1 M is used in standard method for the activation of Nafion [6]. In this work, Nafion membrane will be activated using sulfuric acid in four different concentrations: 1, 2, 3, and 4 M. The effect of sulfuric acid concentration above 1 M on surface morphology of and chemical bonding within activated Nafion will be studied.…”

A Novel Composite Nafion/Anodized Aluminium Oxide Proton Exchange Membrane

“…The first was a typical hydration protocol using successive membrane treatment with H 2 O 2 3%, H 2 SO 4 0.75 M and dH 2 O at 90 °C 25. These membranes (referred below as fully hydrated, FH) were kept in dH 2 O between the tests and their wet weight and in‐plane conductivity ( σ IP ) were measured before and after all the through‐plane conductivity ( σ TP ) measurement, to monitor any change in the membrane condition.…”