Effect of pore-directing agents and silanol groups in

mesoporous silica nanoparticles as Nafion fillers on the

performance of DMFCs

Ciao-Wei Yanga, Kuei-Hsien Chenb, and Soofin Chenga, *

aDepartment of Chemistry, National Taiwan University, Taipei 10617, Taiwan

bInstitute of Atomic & Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan

Supporting information

Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2016

Table S1 The average thicknesses (μm) from five points of various membranes after drying at room temperature overnight.Membrane Ave Thickness (μm) Membrane Ave Thickness (μm)

N117 198±2 recasting 201±10

1%-Ex-SBA-15n 200±7 1%-S-SBA-15n 188±5

2.5%-Ex-SBA-15n 201±5 2.5%-S-SBA-15n 199±2

5%-Ex-SBA-15n 211±6 5%-S-SBA-15n 213±9

10%-Ex-SBA-15n 212±7 10%-S-SBA-15n 223±7

15%-Ex-SBA-15n 228±11 15%-S-SBA-15n 224±6

20%-Ex-SBA-15n 236±12 20%-S-SBA-15n 231±5

1%-Ex-MSN 177±4 1%-S-MSN 186±42.5%-Ex-MSN 199±6 2.5%-S-MSN 197±95%-Ex-MSN 195±14 5%-S-MSN 210±810%-Ex-MSN 210±4 10%-S-MSN 216±4

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0-2

-1

0

1

2

3

4

5

-Z'' (

Ohm

)

Z' (Ohm)

N117 recasting 1%-Ex-SBA-15n 2.5%-Ex-SBA-15n 5%-Ex-SBA-15n 10%-Ex-SBA-15n 15%-Ex-SBA-15n 20%-Ex-SBA-15n

(A)

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0-2

-1

0

1

2

3

4

5

-Z'' (

Ohm

)

Z' (Ohm)

N117 recasting 1%-S-SBA-15n 2.5%-S-SBA-15n 5%-S-SBA-15n 10%-S-SBA-15n 15%-S-SBA-15n 20%-S-SBA-15n

(B)

Fig. S1 Nyquist plot of (A) x%-Ex-SBA-15n and (B) x%-S-SBA-15 with different loadings in

comparison to those with Nafion®117 and recasting Nafion membranes at 60 oC and 90% percentage

humidity.

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0-2

-1

0

1

2

3

4

5

-Z'' (

Ohm

)

Z' (Ohm)

N117 recasting 1%-Ex-MSN 2.5%-Ex-MSN 5%-Ex-MSN 10%-Ex-MSN

(A)

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0-2

-1

0

1

2

3

4

5

-Z'' (

Ohm

)

Z' (Ohm)

N117 recasting 1%-S-MSN 2.5%-S-MSN 5%-S-MSN 10%-S-MSN

(B)

Fig. S2 Nyquist plot of (A) x%-Ex-MSN and (B) x%-S-MSN with different loadings in comparison to

those with Nafion®117 and recasting Nafion membranes at 60 oC and 90% percentage humidity.

Fig. S3 Mapping photographs of silicon in the cross-sections of composite membranes with different

loadings of Ex-SBA-15n (a) 1%, (b) 2.5%, (c) 5%, (d) 10%, (e) 15% and (f) 20%.

Fig. S4 Mapping photographs of silicon in the cross-sections of composite membranes with different

loadings of S-SBA-15n (a)1%, (b) 2.5%, (c) 5%, (d) 10%, (e) 15% and (f) 20%.

Fig. S5 Mapping photographs of silicon in the cross-sections of composite membranes with different

loadings of Ex-MSN (a) 1%, (b) 2.5%, (c) 5% and (d) 10%

Fig. S6 Mapping photographs of silicon in the cross-sections of composite membranes with different

loadings of S-MSN (a) 1%, (b) 2.5%, (c) 5% and (d) 10%.

0 10 20 30 40 50 60 70 80 90 10002468

1012141618

(A)

Stre

ss (M

Pa)

Strain (%)

N117 recasting 1%-Ex-SBA-15n 5%-Ex-SBA-15n 10%-Ex-SBA-15n 15%-Ex-SBA-15n 20%-Ex-SBA-15n

0 10 20 30 40 50 60 70 80 90 10002468

1012141618

Stre

ss (M

Pa)

Strain (%)

N117 recasting 1%-S-SBA-15n 5%-S-SBA-15n 10%-S-SBA-15n 15%-S-SBA-15n 20%-S-SBA-15n

(B)

0 10 20 30 40 50 60 70 80 90 1000

2

4

6

8

10

12(C)

Stre

ss (M

Pa)

Strain (%)

N117 recasting 1%-Ex-MSN 2.5%-Ex-MSN 5%-Ex-MSN 10%-Ex-MSN

0 10 20 30 40 50 60 70 80 90 1000

2

4

6

8

10

12(D)

Stre

ss (M

Pa)

Strain (%)

N117 recasting 1%-S-MSN 2-5%-S-MSN 5%-S-MSN 10%-S-MSN

Fig. S7 Stress–strain curves of Nafion membranes with different loadings of (A) Ex-SBA-15n, (B) S-

SBA-15n, (C) Ex-MSN and (D) S-MSN in comparison to those of Nafion® 117 and recast Nafion

membranes.

200 400 600 8000

20

40

60

80

100

Weig

ht %

Temperature (oC)

N117 recasting 1%-Ex-SBA-15n 2.5%-Ex-SBA-15n 5%-Ex-SBA-15n 10%-Ex-SBA-15n

(A)

200 400 600 8000

20

40

60

80

100

N117 recasting 1%-S-SBA-15n 2.5%-S-SBA-15n 5%-S-SBA-15n 10%-S-SBA-15n

Weig

ht %

Temperature (oC)

(B)

200 400 600 800

0

20

40

60

80

100

N117 recasting 1%-Ex-MSN 2.5%-Ex-MSN 5%-Ex-MSN 10%-Ex-MSN

Weig

ht %

Temperature (oC)

(C)

200 400 600 8000

20

40

60

80

100

N117 recasting 1%-S-MSN 2.5%-S-MSN 5%-S-MSN 10%-S-MSN

Weig

ht %

Temperature (oC)

(D)

Fig. S8 TGA curves of Nafion membranes with different loadings of (A) Ex-SBA-15n, (B) S-SBA-

15n, (C) Ex-MSN and (D) S-MSN in comparison to those of Nafion® 117 and recast Nafion

membranes.

2.70 2.85 3.00 3.15-4.2

-4.0

-3.8

-3.6

-3.4

-3.2

lnσ

1/T(103 K-1)

Fig. S9 Temperature dependence of the proton conductivities for Nafion 117 (), recasting Nafion

membrane (), 5%-Ex-SBA-15n (◇), 5%-S-SBA-15n (◆), 5%-Ex-MSN () and 5%-S-MSN (▲)

composite membranes.