Kim Ae Rhan, Yoo Dong Jin
Department of Bioenvironmental Chemistry and R&D Center for CANUTECH, Business Incubation Center, Chonbuk National University, Jeollabuk⁻do 54896, Korea.
Graduate School, Department of Energy Storage/Conversion Engineering and Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeollabuk-do 54896, Korea.
Polymers (Basel). 2019 Mar 21;11(3):536. doi: 10.3390/polym11030536.
The composite structure, good porosity, and electrochemical behavior of proton exchange membranes (PEMs) are important characteristics, which can improve the performance of polymer electrolyte fuel cells (PEFCs). In this study, we designed and synthesized an XY block copolymer via a polycondensation reaction that contains sulfonated poly(ether ether ketone) (SPEEK) (X) as a hydrophilic unit and a fluorinated oligomer (Y) as a hydrophobic unit. The prepared XY block copolymer is composed of Fe₃O₄ nanoparticles to create composite architecture, which was subsequently treated with a 1 M H₂SO₄ solution at 70 °C for 1 h to eliminate Fe₃O₄ and generate a pores structure in the membrane. The morphological, physiochemical, thermomechanical, and electrochemical properties of bare XY, XY/Fe₃O₄-9 and XY(porous)-9 membranes were measured and compared in detail. Compared with XY/Fe₃O₄-9 composite, the proton conductivity of XY(porous)-9 membrane was remarkably enhanced as a result of the existence of pores as nano-conducting channels. Similarly, the XY(porous)-9 membrane exhibited enhanced water retention and ion exchange capacity among the prepared membranes. However, the PEFC power density of XY(porous)-9 membrane was still lower than that of XY/Fe₃O₄-9 membrane at 60 °C and 60% relative humidity. Also, the durability of XY(porous)-9 membrane is found to be lower compared with pristine XY and XY/Fe₃O₄-9 membranes as a result of the hydrogen crossover through the pores of the membrane.
质子交换膜（PEMs）的复合结构、良好的孔隙率和电化学行为是重要特性，这些特性能够提高聚合物电解质燃料电池（PEFCs）的性能。在本研究中，我们通过缩聚反应设计并合成了一种XY嵌段共聚物，其包含作为亲水单元的磺化聚（醚醚酮）（SPEEK）（X）和作为疏水单元的氟化低聚物（Y）。所制备的XY嵌段共聚物由Fe₃O₄纳米颗粒组成以形成复合结构，随后将其在70℃下用1 M H₂SO₄溶液处理1小时以去除Fe₃O₄并在膜中产生孔隙结构。详细测量并比较了纯XY、XY/Fe₃O₄-9和XY（多孔）-9膜的形态、物理化学、热机械和电化学性能。与XY/Fe₃O₄-9复合材料相比，由于存在作为纳米导电通道的孔隙，XY（多孔）-9膜的质子传导率显著提高。同样，在制备的膜中，XY（多孔）-9膜表现出增强的保水性和离子交换容量。然而，在60℃和60%相对湿度下，XY（多孔）-9膜的PEFC功率密度仍低于XY/Fe₃O₄-9膜。此外，由于氢通过膜的孔隙渗透，发现XY（多孔）-9膜的耐久性低于原始XY和XY/Fe₃O₄-9膜。
