sevda akay. eia sunum · microsoft powerpoint - sevda akay. eia sunum author: enica created date:...

Sevda AkaySevda Akay

Fatih University, Istanbul,TURKEY

Proton Conductivity Studies of Novel OrganicProton Conductivity Studies of Novel OrganicPolymerPolymer

Content

Fuel Cells

Proton Exchange Membrane

Benzimidazole Nitronyl Nitroxides

Synthesis of Novel Organic Polymer (SBNN1)

Electrochemical Impedance Analysis of SBNN1

Conclusions

Acknowledgement

Fuel CellsCells

http://www.carblogindia.com/wpcontent/uploads/2011/02/fuelcell_thumb.jpg

What is function of protonexchange membrane (PEM) infuel cells?

Benzimidazole Nitronyl Nitroxides

-Analogues of nitronyl nitroxide radicals (NNs)-Highly resonance stabilized radicals (two equivalent NO groups and oflarge negative charges on O atom)-High spin density

Proton Conductivity Mechanismof SBNN1

N

N

O

O

O

H

H+

N

N

O

O

O

H

N

N

O

O

O

H ...

......

Thermal Stability of SBNN1

0 100 200 300 400 500 600 700 800

20

30

40

50

60

70

80

90

100

110

We

igh

t(%

)

Temperature (oC)

Commercial PolymerSBNN1

Purchased aldehyde hasbeen found to retain 100% of the mass up to about250 oC. It was observed tolose 5 % of its mass at 340oC, about 62 % at 500 oC,

SBNN is stable up to 150°C, it has lost some massgradually from beginningof 100 °C. It only lost 5%of its mass upto 240oCwhic is mostly associatedwith absorbed water.

The mass loss becamemore pronounced after400 oC. This polymer lost51 % of its mass at 500oC.

Impedance MeasurementsComparison between Nafion and SBNN1

0 1 2 30,0

0,5

1,0

1,5

-Z

''/M

Z' /M

SBNN1, N2

Nafion,N2

0 100 200 300 400 5000

100

200

Z' /M

SBNN1

Nafion

air

Measurements in hydrogenMeasurements of SBNN1 in dry H2 show that the materialSBNN1 has proton conductivity, which increases with theincrease of the gas flow

0 250 500 7500

150

300

40% H2

Z' / M

25% H230% H2

SBNN1, dry H2, room tCo

Impedance diagram of sample SBNN1 in dry hydrogen at room temperature as a function of theflow:

64 µl/min (○); 48 µl/min (○) , 40 µl/min (○)

demonstrate the existence of protonconductivity in SBNN1.

0 200 400 600 800 10000

100

200

300

400

500

Z' /M

air SBNN1N2

48l/min,dry H2

Impedance diagram of sample Bu1 in different gases:air (○); N2 (▲) and dry H2 (◊)

Conclusion

• The results obtained by impedance spectroscopymeasurements of SBNN1 show that the material hasproton conductivity. It is much lower than the onemeasured on Nafion samples prepared by the sametechnological procedure.

Acknowledgements

• Prof. Dr. Zdravko Stoynov

• Prof. Dr. Daria Vladikova

• Assoc. Prof. Dr. Burak Esat

• Dr. Emiliya Mladenova

• Ivaylo Genov

Thank you for listeningThank you for listening……

Synthesis of Novel Organic Polymer(SBNN1)