The document summarizes the synthesis and characterization of a Poly(AAc-co-DMAPMA) (PADMA) hydrogel membrane for use as an ion exchange membrane in fuel cells. PADMA membrane was synthesized via free radical polymerization and characterized using SEM, TGA, compression testing, and ionic conductivity measurements. SEM showed the membrane has a nanogel structure capable of accommodating water or electrolyte. TGA found it thermally stable to 190°C. Testing indicated the membrane could function as both a proton and hydroxyl ion conductor, making it a potential low-cost alternative to Nafion membranes.

1. Poly(AAc-co-DMAPMA): A cost effective ion
exchange membrane for fuel cell application
A.Das1, A. Verma2, K. Scot3, S. Suddhasatwa Basu1*
1Indian
Institute of Technology Delhi
2Indian Institute of Technology Guwahati
3University of Newcastle Upon Tyne
December 10-12, 2013, ICAER, IIT Bombay, India
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

2. Fuel Cell Program at IIT Delhi
• Direct alcohol PEM fuel cell – Anode electrocatalyst, DEFC
• Direct Glucose AEM fuel cell – electrocatalyst, micro DGFC
• PEMFC – cathode electrode degradation, Non PGM catalyst
• PEMWE/SOEC – electrocatalyst for Hydrogen generation
• SOFC - LT/IT-SOFC – electrolyte, electrocatalyst – cathode
- HT SOFC – Ni-YSZ anode instability and mitigation
- HT SOFC – Electrolyte supported cell
- Direct Hydrocarbon - anode development
• CO2 electro-reduction – artificial leaf
• Mathematical modeling of PEMFC/SOFC - overpotentials
PEMFC Material and Cell Testing
 Catalyst support – CNx, f-Gr (chemically), f-MWCNT
 Catalyst – PGM/Non-PGM – Pt-Re,Pt-Sn,Pt-Ir; MnO2, PA-Mn-Cu
 Electrolyte – high temperature PEM
SOFC Material and
Cell Testing
Electrolyte
• YSZ, SDC, GDC
Cathode
• MIEC
• Sr doped LaMnO3
(LSM)
• La1-xSrxCo1-yFeyO 3-!,
(LSCF)
•PCGO, TCGO
Anode
• Ni-YSZ, Ni-SDC
• Cu-Co/Ceria; FeCo/Ceria
• Titanates - LST, LYST
Dissemination (Fuel Cell)
• Publication – IJHE, JPS, Electrochim Acta, etc; h-index – 20; Conferences –ISE, GRC, MRS, ECS,Grove
• Patent – two granted
• Ph.D. thesis 9 completed, 9 in progress ; Post-doctoral fellow 5; M.Tech. thesis 21
• Exchanges – 10 with NCL, LTU, ICL
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

3. Proton Exchange Membrane Fuel Cell (PEMFC)
eLoa
d
Wate
r
4
1
Fuel
(H2)
3
2
5
Oxidant
O2/Air
H2
2 H+ + 2e2 H+ + 1/2 O2 + 2eH2O
H2 + 1/2 O2
H2O
1. Fuel chamber
2. Oxidant chamber
3. Anode (Pt)
4. Electrolyte (PEM)
5. Cathode (Pt/C)
(Anode, Pt)
(Cathode, Pt)
(Overall)
Advantages
 Efficient Power Generation
 Environmental Friendly
 Automobile
 Distributed Power Gen.
 Portable Electronics Eqpt.
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

4. Polymer Electrolyte Membrane (PEM)
Perfluro-sulphonic Acid Membrane
PEM
Anode
MEA
Cathode
70 oC, 1 Bar
Hydrophilic part
Hydrophobic part
PEM
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

5. Advantages of High Temperature PEM

Kinetics of both the electrode reactions enhanced

Tolerance of the Platinum electrodes to CO increased

Non-noble metal catalysts may be used

Integration of reformer technology simpler

Cooling system for facilitating heat dissipation simplified.

Present commercial PEM not suitable for the temperature higher
than 1000C due to dehydration of the membrane

PBI and other organic membranes have serious problem – such
as leaching of phosphoric acid
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

6. Previous Works
Strategy to work on high temperature electrolyte
(i) Modified perfluorosulphonated membranes
(ii) Alternative sulphonated polymers and their composites
(iii) Acid-base polymer membranes and their composites.
Objective
 Synthesis of the poly(AAc-co-DMAPMA) (PADMA) hydrogel membrane
 Preliminary characterization of the membrane for PEMFC use
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

7. Experimental
Acrylic Acid (25.8 % mole) + [dimethylamino) propyl]-methacrylamide
(DMAPMA) (4.2 % mole) mixed in cold condition over magnetic stirrer
Distill water (70 % mole) added & mixed thoroughly
N2 gas purged for 15 min.
Added: conc. aq. solution of ammonium persulphate (APS – 0.50 mol % of
total monomer) as initiator and N,N,N’,N’-tetramethyl ethylene diamine
(TEMED -1 mol %) as accelerator.
Reaction mixture transferred into a mold of PTFE, placed in water bath at 41 ± 10C
Membrane removed from mold and cut into pieces
Washed in regularly changed distilled water for 3 days and dried in vacuum
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

8. Reaction Schemen: Synthesis of Poly(AAc-coDMAPMA) Hydrogel Membrane
H
H2C
C
+
C
O
H
(AAc)
CH3
H2C
APS-TEMED
41±1°C, 24 h
C
C
O
CH3
O
NH
(CH2)3
( H2C
CH )
m
CO2H
( H2C
C
)n
C
O
NH
N
(CH2)3
CH3 CH3
N
(DMAPMA)
CH3 CH3
Poly(AAc-co-DMAPMA)
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

9. SEM of PADMA Membrane
 made up of closely packed nanogels of ~300 nm
diameter
 Macroporous: enough space to accommodate water
or suitable electrolyte
 Densely packed - may not allow the fuel to pass
through and at the same time the inner structure may help
to improve the conductivity.
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

10. TG for PADMA Membrane
Membrane is thermally stable up to 190oC, thereafter the
polymer chain degradation starts
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

11. Stress-strain Curve for Swollen PADMA Membrane
No fracture of
membrane was
observed
 Elastic modulus of the membrane found to be around 16.0-24.0 kPa
(cf. Nafion ~ 0.5 - 1.28 MPa)
 Shear-stress curve of the membrane indicates good tenacity up to 5
kPa stress
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

12. Ionic Conductivity of PADMA Membranes
1.E+00
PADMA; Temp = 25 °C
PADMA; Temp = 60 °C
Nafion; Temp = 60 °C
Nafion; Temp = 80 °C
Conductivity (S/cm)
PADMA; Temp = 80 °C
Nafion; Temp = 25 °C
1.E-01
PADMA; Temp = 40 °C
Heat treated PADMA; Temp = 80 °C
 EIS: 100 Hz and 30 kHz
 PADMA : 625 mm thick
 Nafion®512: 133 mm thick
1.E-02
1.E-03
Water starved condition:
RH = 39%
1.E-04
1.E-05
1.E-06
1
3
5
7
9
11
pH
Increase in ionic conductivity of PADMA membrane at low (2.2) and high
(10.6) pH indicates that the membrane may work both as proton and
hydroxyl ion conductor.
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

13. pH Effect
Predominant molecular composition of PADMA membrane in buffers of
various pH values: a) pH < 3.5; b) pH=3.5; c) pH > 3.5.
a
b
CH3
( CH2
CH )m ( CH2
C
)n
( CH2
CH )m ( CH
C
2
CO
CO2H
O
+
CH3
H
( CH2
CH )m ( CH
2
O-
O
N
CH3
C
pH=3.5
CH3
H
)n
CO
C
HN
+
N
pH<3.5
)n
CH3
CO
C
HN
c
CH3
O-
HN
N
CH3
Poly(AAc-co-DMAPMA)
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India
pH>3.5
CH3 CH3

14. Summary
 PADMA hydrogel membrane successfully synthesized
 PAMMA Membrane characterized using SEM,
compression testing, TGA and Ionic conductivity
 Investigation points out that PADMA membrane would
work as a good matrix for membrane electrolyte
 Membrane may work as both proton and hydroxyl ion
exchange membrane
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

15. Acknowledgement
MNRE, DST, UKIERI, Shell Hydrogen, CSIR, ISRO, DIT, EPSRC (UK)
9 Ph.D. Students
5 Post-doc
4 M.Tech students
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India

16. Fuel cell group at IIT Delhi
Ph.D Students
Post-Doctoral Fellows
Varagunapandiyan N
Rajelakshmi pillai
Debika Basu
Pankaj Kumar Tiwari
Rahul Pal
Gurpreet Kaur
Merajul Islam
Jyoti Goel
Dyuti Pandey
Shaneeth (part time)
Mridul Kumar
Amandeep Jindal
Harikrishnan N
Neetu Kumari
Department of Chemical Engineering
Indian Institute of Technology-Delhi, New Delhi 110 016, India