Measurement of hydrogen ion conductivity through proton exchange membrane
Proton exchange membrane is the prime part of proton exchange membrane fuel cell (PEMFC). In this work, it has focused to the proton conduction through two different conductive polymer membranes such as Nafion 212 and Fumapem AM (PBI). The conductivity has measured by the two probe method with the help of electrochemical impedance spectroscopic (EIS) analysis. To increase the conductivity, Fumapem AM (PBI) membrane has been doped with 85 % concentrated H3PO4 acid at ambient temperature. Due to acid doping, it has swelled 41 % compare to prior on. The highest conductivity has recorded as 3.54 and 2.24 mS/cm under 60 °C temperature for Nafion 212 and Fumapem AM (PBI) respectively. The proton conductivity of both membranes is fully dependent on the surrounding temperature.
Novel Polymer Electrolyte Membranes for Automotive Applications – Requirements and Benefits
During the past few years, the feasibility of using polymer electrolyte fuel cells in automotive power trains at an impressive performance level has been proven repeatedly. However, current fuel cell stacks are still largely based on decade‐old polymer electrolyte membrane technology thus limiting performance, durability, reliability, and cost of the fuel cell systems. The major challenge for membrane R&D constitutes the demand for polymer electrolytes that allow for system operation at higher temperatures and lower water management requirements without increased conduction losses. None the less, demanding automotive requirements will not compromise on other properties such as mechanical and chemical stability and gas permeability.
Inhibition of Mild Steel Corrosion Using L-tryptophan and Synergistic Surfactant Additives
The corrosion inhibition characteristics of nitrogen containing amino acid L-tryptophan on mild steel in 0.1 M HCl solution, in the temperature range of 30-50 o C, was studied by weight loss and potentiodynamic polarization measurements. L-tryptophan significantly reduces the corrosion rates of mild steel; the maximum inhibition efficiency being 83% at 50 o C in presence of inhibitor concentration of 500 ppm. The effect of the addition of very small concentrations of anionic surfactant, sodium dodecyl sulfate (SDS), and of cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), on the corrosion inhibition behavior of L-tryptophan was also studied. The inhibition efficiency (IE) of L-tryptophan significantly improved in presence of both surfactants. The effect of SDS and CTAB on the corrosion inhibition behavior of L-tryptophan appears to be synergistic in nature, the values of synergism parameter being greater than unity. The adsorption of inhibitors on mild steel surface obeyed Langmuir’s adsorption isotherm. The calculated thermodynamic parameters for adsorption reveal a strong interaction between the inhibitors and the mild steel surface. The results obtained by electrochemical studies are consistent with the results of the weight loss measurements. L-tryptophan acts more anodic than cathodic inhibitor.