Improved electrochemical performance of composite anion exchange membranes for fuel cells through cross linking of the polymer chain with functionalized graphene oxide

Enhanced Hydroxide Conductivity and Dimensional Stability with Blended Membranes Containing Hyperbranched PAES/Linear PPO as Anion Exchange Membranes

“…As shown in Scheme S1 , for chloromethylation, the CM-PPO copolymer was synthesized via the Friedel-Crafts alkylation [ 6 , 41 ]. The PPO polymer (3.00 g, 0.10 mmol) was dissolved in TCE (15.0 mL) at 30 °C in a two-neck round-bottomed flask equipped with a reflux condenser under nitrogen.…”

“…The IEC values of the Q-PAES/PPO-XY membranes were calculated using the following equation: IEC (mmol g −1 ) = (C HCl × V HCl − C NaOH × V NaOH )/M dry where C HCl and C NaOH denote the molar concentrations of HCl and NaOH solutions, respectively, and V HCl and V NaOH refer to the volumes of HCl and NaOH solution reaching the equivalent point. The alkaline stability of Q-PAES/PPO-XY blended membranes was monitored by soaking them in a 2.0 M KOH solution at 50 °C for 1000 h. The blended membranes were removed from the alkaline solution, and washed repeatedly with DI water [ 6 ]. The FT-IR spectra, IEC, and TGA of the samples were observed at 200 h intervals throughout the alkaline stability test.…”

“…Among the various existing FCs, cation exchange membrane fuel cells (CEMFCs) have received particular attention due to their many advantages, such as high power density and superior efficiency [ 4 , 5 ]. Despite these advantages, the commercialization of the CEMFC has been difficult due to the high system costs associated with the use of precious metal platinum catalysts and fluorinated membranes [ 6 ]. On the other hand, anion exchange membrane fuel cells (AEMFCs) are capable of reducing system costs by using less valuable metal catalysts (Co and Ni) [ 7 ] and have been studied recently due to their advantages, including fast oxygen reduction reactions (ORR) at the cathode, low fuel crossover, and easy water management.…”

“…However, a high IEC value causes excessive dimensional change in the membrane along with a high water uptake, which leads to separation of the membrane electrode assembly (MEA) during the manufacture and deterioration of fuel cell durability from the wet-dry repetition [ 13 , 14 ]. As mentioned above, various studies have achieved excellent dimensional stability along with high IEC values such as blended membranes [ 15 , 16 , 17 , 18 ]; inorganic/organic composite membranes [ 6 , 19 , 20 ]; and the backbone design of comb-shaped [ 21 , 22 , 23 ], branching [ 24 , 25 , 26 ], and cross-linking [ 27 , 28 ].…”

Diffusion Dialysis for Acid Recovery from Acidic Waste Solutions: Anion Exchange Membranes and Technology Integration

“…AEMs as one kind of ion exchange membranes containing positively charge groups allow the migration of anions and repel cations. In fact, AEMs have already attracted much attention in various areas, such as desalination [ 27 ], alkaline fuel cells [ 28 , 29 , 30 ], wastewater treatment [ 31 , 32 ] and so on. At present, some commercial AEMs, including Selemion DSV (Asahi Glass, Tokyo, Japan), Neosepata AFX/N (Tokuyama Co., Tokyo, Japan) and DF120 (Shandong Tianwei Membrane Technology Co., Weifang, China) series are available for recovering acids.…”