Supplementary Materials:

Poly(arlyene ether sulfone) based semi-interpenetrating

polymer network membranes containing cross-linked

poly(vinyl phosphonic acid) chains for fuel cell

applications at high temperature and low humidity

conditions

Kihyun Kima, Pilwon Heob, Taeyun Koa, Ki-hyun Kimb, Sung-Kon Kima, Chanho Pakb ,and

Jong-Chan Leea*

a Department of Chemical and Biological Engineering and Institute of Chemical Processes,

Seoul National University, 599 Gwanak–ro, Gwanak–gu, Seoul 151–744, Republic of Korea

b Energy Lab., Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd.,

Electronic Materials Research Complex, 130 Samsung-ro, Gyeonggi-do, 443-803, Republic

of Korea

Corresponding Author: Tel. +82 2 880 7070 / fax: +82 2 880 8899; e-mail: jongchan@snu.ac.kr

Captions of supplementary figures

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Figure S1. Synthesis of SPAES polymer.

Figure S2. 1H NMR spectrum of SPAES.

Figure S3. Infrared spectra of VPA-based solution containing BMAEP and thermal initiator

(AIBN). (a) Before thermal treatment (b) after thermal treatment at 80 oC for 24 h. (c) Photo

images of VPA-based solution after thermal treatment at 80 oC for 24 h.

Figure S4. Photo and SEM images (surface and cross-section) of the membranes with

various weight ratios of SPAES to VPA. (a) VPA0 (SPAES: VPA = 1: 0, SPAES) (b) VPA1.0

(SPAES: VPA = 1: 1, B15) (c) VPA1.5 (SPAES: VPA = 1: 1.5) (d) VPA2.0 (SPAES: VPA = 1:

2). Molar content of BMAEP in the all semi-IPN membranes is 0.15 mol of VPA.

Figure S5. Photo image of semi-IPN membrane using divinyl benzene as a cross-linker.

Figure S6. Durability test (OCV holding method involving the continual I-V measurements)

of the MEAs prepared using recast-Nafion® and SPAES membranes at 120 °C and 40% RH

for 100 h. Arrow on figure denotes the region induced by temporary recording error.

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Figure S1.

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Figure S2.

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Figure S3.

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Figure S4.

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Figure S5.

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Figure S6.

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Table S1 Results of oxidative stability test and hydrogen cross-over measurement.

Membrane Residual weighta

(%)

Hydrogen cross-overb (mA cm-2)

200c (mV) 500c (mV)

SPAES 83 0.2 0.3

B15 83 0.2 0.3

Recast-Nafion® 98 1.3 1.8

a Obtained by Fenton’s test.

b Measured at the beginning of the operation at 120 oC and 40% RH.

c Applied DC voltages between the electrodes.

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