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Synthesis of new proton conducting membranes for
Fuel Cells
PhD student Simona Ceresa Mio I.F.M. Chemistry
Department
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SUMMARY

• introduction
• how a Fuel Cell works
• types of Fuel Cells
• about PEMFC
• sulfonation of polymers
• about synthesis of new PEEKs
• conclusions

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FUEL CELLS
HOW A FUEL CELL WORKS
This clean technology directly transforms the
chemical potential energy into electric, by means
of a redox process that, being involved hydrogen
like fuel and oxygen like oxidant, achieves
electricity generation and water forming as a
final by-product, remarkably reducing harmful gas
emissions.
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TYPES OF FUEL CELLS

• SOFC Solid Oxide FC
• AFC Alkaline FC
• PAFC Phosphoric Acid FC
• MCFC Molten Carbonate FC
• PEMFC Proton Exchange Membrane FC

In the technological research of the energetic
field, PEMFC have the greatest interest, because
they have a lot of applications that go from the
mobile telephony to the motors for vehicles
these cells comes today experimented succesfully
in many special vehicles, cars and bus.
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CHARACTERISTICS of PEMFC

• high proton conductivity
• elevated chemical stability
• greater duration of ten years
• low cost

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PROTON EXCHANGE MEMBRANE FC
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Drawbacks of PEMFC

• high costs of investment

• fuel (H2 without impurities in order to not
  poison the catalyst) and its storage

• the management of the produced water

• good system of cooling

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Du Ponts Nafion
drawbacks

• and high cost, and this is the major obstacle for
  widespread application in automotive
  FC.

• loss of protonic conductivity obove 80C

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MOLECULAR STRUCTURE of PEEK-WC
One of the ways considered to be capable of
bringing good results is using sulphonated
polymers with a high resistance to thermical
oxidation
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SULFONATION of PEEK-WC
Up to now, two different sulfonation procedures
were tested

• In the first one method chlorosulphonic acid at
  room temperature is used in large excess
  (heterogeneous reaction), degradation of polymers
  during the reaction is not observed, but is
  difficult to reproduce sulfonated polymers with
  the same degrees of sulfonation.

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SULFONATION of PEEK-WC

• In the second one polymer is dissolved in
  dichloromethane and then a solution of
  cholorosulfonic acid in dichloromethane is added
  dropwise under stirring at room temperature

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FTIR of sulfonated PEEK-WC
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(No Transcript)
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TGA of sulfonated PEEK-WC under air flow,
T10C/min
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Solubility of sulfonated PEEK-WC at two different
degrees of sulfonation
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comparison between conductivity of Nafion and
sulfonated PEEK-WC membranes
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Permeability values for several pure gases and
vapors measured at 25C through the sulfonated
PEEK-WC membranes with a level of sulfonation of
the 70 and through Nafion117
aPermeability unit (cm-3(STP) cm/cm2 s Torr).1010
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SYNTHESIS of POLYMER
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SYNTHESIS of PES
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PHYLLOSILICATE NANOCOMPOSITES
Organic phase
Composite membranes

• Mica
• Montmorrillonite
• Saponite

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CONCLUSIONS

• Several sulfonated derivatives of PEEK-WC were
  obtained with different degrees of sulfonation
  (DS) and their properties are under testing and
  more relevant results are expected. Proton
  conductivity of sulfonated derivatives is a
  direct function of the DS.

• Sulfonated derivatives of PEEK-WC present lower
  permeability to CH3OH (for application in DMFC)
  and working temperatures up to 120C

• A series of new PEEKs and PES with different
  substituent groups were synthetised, and they are
  under testing

• new polymer layered silicate nanocomposites

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Future plans

• synthesis of new conducting polymers
• optimization of the reaction of sulfonation of
  PEEK-WC

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THANKS