State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University , Shanghai 200433, People's Republic of China.
ACS Appl Mater Interfaces. 2017 Aug 9;9(31):26077-26087. doi: 10.1021/acsami.7b07651. Epub 2017 Jul 28.
Metal-organic frameworks (MOFs) are being intensively explored as filler materials for polymeric proton exchange membranes (PEMs) due to their potentials for the systematic design and modification of proton-conducting properties. S-UiO-66, a stable MOF with functional groups of -SOH in its ligands, was selected here to prepare S-UiO-66@graphene oxide (GO) hybrid nanosheets via a facile in situ growth procedure, and then a series of composite PEMs were prepared by hybridizing S-UiO-66@GO and sulfonated poly(ether ether ketone) (SPEEK). The resultant hybrid nanosheets not only possessed abundant -SOH groups derived from the ligands of S-UiO-66 but also yielded a uniform dispersion of S-UiO-66 onto GO nanosheets, thus effectively eliminating the agglomeration of S-UiO-66 in the membrane matrix. Thanks to the well-tailored chemical composition and nanostructure of S-UiO-66@GO, the as-prepared SPEEK/S-UiO-66@GO composite PEMs present a significant increase in their proton conductivity under various conditions. In particular, the proton conductivity of the SPEEK/S-UiO-66@GO-10 membrane was up to 0.268 S·cm and 16.57 mS·cm at 70 °C-95% RH and 100 °C-40% RH (2.6 and 6.0 times that of recast SPEEK under the same condition), respectively. Moreover, the mechanical property of composite membranes was substantially strengthened and the methanol penetration was well-suppressed. Our investigation indicates the great potential of S-UiO-66@GO in fabricating composite PEMs and also reveals that the high proton conductivity of MOFs can be fully utilized by means of MOF/polymer composite membranes.
金属有机骨架（MOFs）因其具有系统设计和修饰质子传导性能的潜力，正被作为填充材料被深入探索应用于聚合物质子交换膜（PEMs）中。本研究选择了具有-SOH 官能团的稳定 MOF（S-UiO-66），通过简便的原位生长法制备 S-UiO-66@氧化石墨烯（GO）杂化纳米片，然后通过杂化 S-UiO-66@GO 和磺化聚醚醚酮（SPEEK）制备了一系列复合 PEMs。所得的杂化纳米片不仅具有丰富的来源于 S-UiO-66 配体的-SOH 基团，而且使 S-UiO-66 在 GO 纳米片上均匀分散，从而有效消除了 S-UiO-66 在膜基质中的团聚。得益于 S-UiO-66@GO 的精心设计的化学组成和纳米结构，所制备的 SPEEK/S-UiO-66@GO 复合 PEMs 在各种条件下均表现出质子电导率的显著提高。特别是，SPEEK/S-UiO-66@GO-10 膜在 70°C-95%RH 和 100°C-40%RH 下的质子电导率分别高达 0.268 S·cm 和 16.57 mS·cm（在相同条件下是再铸 SPEEK 的 2.6 和 6.0 倍）。此外，复合膜的机械性能得到了显著增强，甲醇渗透率也得到了很好的抑制。我们的研究表明了 S-UiO-66@GO 在制备复合 PEMs 方面的巨大潜力，也揭示了 MOFs 的高质子电导率可以通过 MOF/聚合物复合膜充分利用。
