Abstract It has been reported that introducing graphene oxide (GO) or functionalized GO into proton exchange membranes (PEMs) can inhibit methanol diffusion by increasing the complexity of the methanol diffusion pathway in the hydrophilic region. In fact, methanol permeation also occurs in the hydrophobic area, which is very important, but rarely studied. In this study, we propose a facile and effective in-situ cross-linking method to prepare GO/sulfonated poly (p-phenylene-co-aryl ether ketone) crosslinked PEMs. By using the sulfonic acid group in parent polymer as a solid acid catalyst, the –COOH groups in GO undergo the Friedel-Craft acylation with the nucleophilic phenyl rings in the hydrophobic segments under vacuum heating, and the construction of covalent cross-linking network between GO and hydrophobic region is achieved successfully. The obtained crosslinked membranes show obviously reduced methanol crossover and greatly enhanced selectivity. The highest power density of the passive DMFC is obtained by using the 2 wt% GO crosslinked membrane and its value (28.1 mW cm-2) is higher than the original parent polymer (24.4 mW cm-2). These results demonstrate that the hydrophobic phase is closely relevant to the transport of methanol molecules in the membrane, which provides a new idea for the construction of methanol-blocking PEMs.

中文翻译：

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通过磺化聚（对亚苯基-共芳基醚酮）和氧化石墨烯（GO）纳米片的原位交联提高质子/甲醇选择性

摘要 据报道，将氧化石墨烯 (GO) 或功能化 GO 引入质子交换膜 (PEM) 可以通过增加亲水区甲醇扩散途径的复杂性来抑制甲醇扩散。事实上，甲醇渗透也发生在疏水区，这一点很重要，但很少研究。在这项研究中，我们提出了一种简便有效的原位交联方法来制备 GO/磺化聚（对亚苯基-共芳基醚酮）交联的 PEM。利用母体聚合物中的磺酸基团作为固体酸催化剂，在真空加热下，GO中的-COOH基团与疏水链段中的亲核苯环发生Friedel-Craft酰化反应，构建了共价交联网络GO和疏水区域成功实现。得到的交联膜显示出明显降低的甲醇渗透和大大提高的选择性。被动 DMFC 的最高功率密度是通过使用 2 wt% GO 交联膜获得的，其值 (28.1 mW cm-2) 高于原始母体聚合物 (24.4 mW cm-2)。这些结果表明疏水相与膜中甲醇分子的传输密切相关，为构建阻断甲醇的PEMs提供了新思路。