Abstract We adopt dissipative particle dynamics simulation technique and systematically study the effect of sequence distributions of hydrophobic and hydrophilic segments in individual sulfonated polyimide (SPI) copolymer on the micro-phase separated structure and the performance of proton exchange membranes (PEMs) under various water contents. The phase morphology as well as the shape and size of water channels is affected by sequence distributions. Compared to the di-block copolymer and the alt-copolymer, water channels in the multi-block copolymer are more homogenous. Additionally, the copolymer sequence distributions affect the water transport which is closely related to the proton conductivity, the dimensional stability and the mechanical properties of PEMs via tuning the phase structure. Generally, the more homogenous water channels the faster water transport. As for the dimensional stability, unlike the other two copolymers the unique shrinkage behavior of multi-block copolymer can resist the membrane swelling induced by water uptake. Moreover, the system with short block has relatively large Young's modulus and the influence of sequence distributions on Young's modulus weakens with the addition of water. Consequently, the multi-block SPI copolymer possesses fast water transport, low dimension-swelling and relatively high Young's modulus, which will make it a potentially huge application in PEM.

中文翻译：

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磺化聚酰亚胺共聚物膜的中尺度建模：序列分布的影响

摘要 我们采用耗散粒子动力学模拟技术，系统研究了单个磺化聚酰亚胺 (SPI) 共聚物中疏水和亲水链段的序列分布对不同含水量下微相分离结构和质子交换膜 (PEM) 性能的影响。 . 相形态以及水通道的形状和大小受序列分布的影响。与二嵌段共聚物和替代共聚物相比，多嵌段共聚物中的水通道更均匀。此外，共聚物序列分布通过调节相结构影响水传输，水传输与质子电导率、尺寸稳定性和 PEM 的机械性能密切相关。一般来说，水道越均匀，水的输送越快。至于尺寸稳定性，与其他两种共聚物不同，多嵌段共聚物独特的收缩行为可以抵抗吸水引起的膜膨胀。此外，短块体系具有较大的杨氏模量，序列分布对杨氏模量的影响随着水的加入而减弱。因此，多嵌段 SPI 共聚物具有快速的水传输、低尺寸膨胀和相对较高的杨氏模量，这将使其在 PEM 中具有潜在的巨大应用。短块体系具有较大的杨氏模量，随着水的加入，序列分布对杨氏模量的影响减弱。因此，多嵌段 SPI 共聚物具有快速的水传输、低尺寸膨胀和相对较高的杨氏模量，这将使其在 PEM 中具有潜在的巨大应用。短块体系具有较大的杨氏模量，随着水的加入，序列分布对杨氏模量的影响减弱。因此，多嵌段 SPI 共聚物具有快速的水传输、低尺寸膨胀和相对较高的杨氏模量，这将使其在 PEM 中具有潜在的巨大应用。