Preactivated zeolite nanosheet plate-tiled membrane on porous PVDF film: Synthesis and study of proton-selective ion conduction
Preactivated zeolite nanosheet plate-tiled membrane on porous PVDF film: Synthesis and study of proton-selective ion conduction
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DOI：
10.1016/j.memsci.2022.121328
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发表时间：
2022-12-27
影响因子：
9.5
通讯作者：
Dong, Junhang
中科院分区：
文献类型：
--
作者：
Iskhakova, Landysh;Cao, Zishu;Dong, Junhang
以液分散的形式直接制备了大面积（-2.0 × 2.0 μ m2）、纳米厚度（-60 nm）的预活化MFI沸石纳米片板（ZNPs）。单个ZNP是由相邻ZN表面之间的Si-O-Si键相互连接的4纳米厚单晶沸石纳米片（ZNs）堆叠而成。分散的开孔ZNP允许在不需要涂覆后活化的情况下将ZNP膜铺在聚合物基底上。采用自修复真空辅助过滤镀膜的方法，在PVDF大孔薄膜上制备了无针孔znp -瓦（ZNPT）膜。得到的ZNPT层厚度为-500 nm，由约7层ZNP组成，ZNP间宽度和ZNP间入口孔隙率分别约为9 nm和2%。在水溶液中，ZNPT-PVDF膜对钒基离子的质子传输具有较高的选择性和较低的质子传导阻力。该膜还被证明可以作为钒氧化还原液流电池的有效离子分离器。本文报道的预活化ZNP悬浮液的合成可能克服了实现聚合物负载ZN膜的主要障碍，即现有方法在获得易分散的开孔ZNs方面效率低下。ZNPT-PVDF膜是一种更经济、更可持续的离子分离膜替代品。
Preactivated MFI zeolite nanosheet plates (ZNPs) with large areas (-2.0 x 2.0 mu m2) and nanometer thicknesses (-60 nm) were prepared directly in liquid-dispersed state. The individual ZNP was a stack of 4-nm-thick single crystalline zeolite nanosheets (ZNs) interlinked by Si-O-Si bonds between neighboring ZN surfaces. The dispersed open-pore ZNPs allowed formulating suspensions for tiling ZNP membranes on polymer substrates without requiring post-coating activation. A pinhole-free ZNP-tiled (ZNPT) membrane has been achieved on macroporous PVDF film by a self-repairing vacuum-assisted filtration coating method. The resultant ZNPT layer was-500 nm-thick consisting of about 7 ZNP layers with inter-ZNP width and inter-ZNP entrance porosity around 9 nm and 2%, respectively. The ZNPT-PVDF membrane exhibited high selectivity to proton transport over vanadyl ion and low resistances to proton conduction in aqueous solutions. The membrane also demon-strated to function as an efficient ion separator for the vanadium redox flow battery. The reported synthesis of preactivated ZNP suspension may overcome the major hurdle to realizing polymer-supported ZN membranes, which is the inefficiency of existing methods in obtaining readily dispersible open-pore ZNs. The ZNPT-PVDF membrane can be a more affordable and sustainable alternative to the Nafion-based ion separation membranes.