Supporting Information

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1 Supporting Information Anion Conductive Triblock Copolymer Membranes with Flexible Multication Side Chain Chen Xiao Lin a,b, Hong Yue Wu a, Ling Li a, Xiu Qin Wang a, Qiu Gen Zhang a, Ai Mei Zhu a, Qing Lin Liu a, * a Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemical & Biochemical Engineering, The College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 00, P. R. China. b Collaborative Innovation Center of Chemistry for Energy Materials (ichem), Xiamen University, Xiamen 00, P. R. China. *Corresponding author: Q.L. Liu, qlliu@xmu.edu.cn, Tel: , Fax: S-

2 Scheme S The route for synthesis of MQA and DQA. Scheme S Synthesis of hydroxyl-terminated PP-H and fluorine-terminated PP-F oligomers. Synthesis of Di-quaternary Ammonium (DQA) Salt Mono-quaternary ammonium (MQA) salt is synthesized according to our previous report, as shown in Scheme S. 0 ml of tetrahydrofuran (THF) was mixed with 0 ml of,-dibromohexane in a flask. Trimethylamine gas was bubbled into the bottom of the flask via a tube by heating a trimethylamine solution. After bubbling for h, the mixture was continued to react at room temperature (RT) for another h. The obtained white precipitate was filtered and wash with THF for three times to remove the unreacted,- dibromohexane. Then, the product (MQA) was dried under vacuum at RT for h (yield: %). ml of TMHDA was mixed with 0 ml of acetonitrile. Then, a mixture of MQA (.0 g) and acetonitrile (0 ml) was added into the TMHDA/acetonitrile solution at 0 o C under vigorous stirring. After h, the product was precipitated by pouring the reaction mixture into anhydrous ether. Subsequently, the precipitate (DQA) was washed with ether and dried in a vacuum oven at RT overnight (yield: 7%). Synthesis of Fluorine-Terminated Mono-Telechelic ligomers (PP-F) Scheme S shows the route for synthesis of PP-F.. g of DMP (0 mmol) was mixed with 00 ml of methanol in a 0 ml flask to form a solution. xygen was bubbled into the bottom of the flask and then a mixture made up of CuCl (0.08 g, 0. 8 mmol), TMEDA (0.8 g,. mmol) and methanol (0 ml) was added into the DMP/methanol solution under stirring. After h, the mixture was filtered and washed with S-

3 methanol to obtain precipitate. Then, the obtained product was dried under vacuum at 0 o C for h to yield hydroxyl-terminated mono-telechelic oligomers (PP-H) (yield: 8%)..00 g of PP-H (.07 mmol),.00 g of HFB (0.7 mmol), 0.0 g of K C (. mmol), ml of toluene and 0 ml of DMF were added into a flask at 80 o C. After 8 h, the product was precipitated in methanol. The precipitate was washed with methanol for several times and dried in an oven at 0 o C for h to obtain off-white PP-F (yield: 7%). Synthesis of Hydroxyl-Terminated Telechelic ligomers (PES-H-x, x=, and 0) The synthetic route of PES-H-x is presented in Scheme. Taking PES-H- as an example,. g of BPHF (0. mmol),. g of FPS (0.0 mmol),.8 g of K C, 0 ml of toluene and 0 ml of DMAc were mixed in a flask equipped with a condenser, a Dean-Stark trap and a magnetic stirrer. Then, the mixture was heated to o C for 0 h. Afterwards, the mixture was poured into methanol to precipitate product. The impurities in the product were removed by washing with methanol. Then, the final product (PES-H-x) was dried at 0 o C for h. The polymerization degree of the PES-H-x was calculated to be x= by the result of H NMR analysis. Herein, hydroxyl-terminated telechelic oligomers with three different polymerization degrees (x=, and 0) were synthesized (yield: 0%). Synthesis of Triblock Copolymers (ABA-x) The synthesis of ABA- is described as follows. PES-H- (.000 g), PP-F (0. g), K C (0.00 g), NMP (0 ml) and cyclohexane ( ml) were mixed in a flask. The mixture was heated to 0 o C to take reaction for h and then cooled to 0 o C, continue reacting for 8 h. Subsequently, the polymer solution was poured into isopropanol to precipitate the polymer. The polymer (ABA-) was washed with methanol to remove impurities and dried under vacuum at 0 o C for h (yield: 8%). Synthesis of Triblock Copolymer Bearing Flexible Side Chain (ABA-CBr-x and ABA-CH -x) The ABA-CBr-x was prepared from ABA-x via Friedel-crafts reaction. Taking ABA-CBr- as an example, ABA- (.00 g), AlCl (. g) and dichloromethane (0 ml) were mixed in a flask. A solution of BHC (. g) and dichloromethane (0 ml) was added into a 0 ml flask. The Friedel-crafts reaction was carried out under stirring at RT. After h, the mixture was poured into petroleum ether to precipitate the product. Finally, the product (ABA-CBr-x) was washed with methanol and dried in a vacuum oven at 0 o C overnight (yield: %). ABA-CBr- (.00 g), triethylsilane (.07 g), dichloromethane (0 ml) and trifluoroacetic acid (0.7 g) were dissolved in a flask equipped with a condenser to take reaction under reflux. The reaction solution S-

4 was boiling during the reaction process. After 8 h, the product was precipitated in methanol and washed with methanol to remove impurities. The final product (ABA-CH -x) was obtained by drying in a vacuum oven at 0 o C overnight (yield: 8%). Synthesis of Triblock Copolymers Bearing Multi-QA Side Chain (ABA-TQA-x) ABA-TQA-x was synthesized via the Menshutkin reaction between ABA-CH -x and DQA. Take ABA- TQA- as an example,.00 g of ABA-CH - (0. mmol -Br groups),. g of DQA (.77 mmol) and 0 ml of NMP were mixed in a flask to take reaction at 0 o C for h. Then, the reaction mixture was coagulated in anhydrous ether and the obtained product (ABA-TQA-x) was washed with deionized water and dried under vacuum at 0 o C overnight (yield: %). 7 Fabrication of Membranes.0 g of ABA-TQA-x copolymer was dissolved in 0 ml of DMS to yield a solution. After being filtrated to remove insoluble impurities, the solution was cast onto glass plates and dried at 0 o C in a vacuum oven for h to give a ~0 μm thick, transparent membrane. The membrane was immersed into a M aqueous KH solution stored in a sealed container to make the ABA-TQA-x membranes in hydroxide form. Then, the membrane was washed with degassed deionized water to remove residual KH and immersed in degassed deionized water under the protection of nitrogen atmosphere for h before measurements H 7, DMS..0.00, Fig. S H NMR spectrum of DQA. S-

5 CHCl (a),.00.8 H (b) 8 7 Fig. S H NMR spectra of the (a) PP-H and (b) PP-F oligomers ,,8,7 CDCl Fig. S C NMR spectrum of the PP-F. S-

6 Table S Molecular weight of PP-H, PP-F and ABA-n copolymers. Copolymers Mn a, kg mol - Mn b, kg mol - Mw b, kg mol - Mw b /Mn b PP-H.... PP-F -... PES-H PES-H-.... PES-H ABA ABA ABA Note: a determined by H NMR, b determined by GPC. CHCl,, Fig. S H NMR spectrum of the PES-H- oligomers. S-

7 CHCl (a) H (b) H Fig. S H NMR spectra of the (a) ABA- and (b) ABA-CBr- copolymers. 0.00, Fig. S H NMR spectrum of ABA-CH -. H 8,,0 S-7

8 0,7 7,,,H,0,, DMS Fig. S7 H NMR spectrum of ABA-TQA-. 0, DMS,H,0 8 7 Fig. S8 H NMR spectrum of ABA-MQA. S-8

9 Water uptake (%) (a) ABA-TQA- ABA-TQA- ABA-TQA-0 ABA-MQA Swelling ratio (%) (b) ABA-TQA- ABA-TQA- ABA-TQA-0 ABA-MQA Temperature ( o C) Temperature ( o C) Fig. S (a) Water uptake and (b) swelling ratio of the AEMs. Br - conductivity (ms cm - ) ABA-TQA- ABA-TQA- ABA-TQA-0 ABA-MQA Temperature ( o C) Fig. S0 The Br conductivity of the AEMs. Cell resistance ( cm ) ABA-TQA- ABA-MQA Current density (ma cm - ) Fig. S Cell resistance of the single cell using the ABA-TQA- and ABA-MQA membranes. References () Lin, C. X.; Huang, X. L.; Guo, D.; Zhang, Q. G.; Zhu, A. M.; Ye, M. L.; Liu, Q. L., Side-Chain-Type Anion Exchange Membranes Bearing Pendant Quaternary Ammonium Groups via Flexible Spacers for Fuel Cells. J. Mater. Chem. A 0, (), 8-8. S-