Flow synthesis of polycrystalline ZIF-8 membranes on polyvinylidene fluoride hollow fibers for recovery of hydrogen and propylene
Flow synthesis of polycrystalline ZIF-8 membranes on polyvinylidene fluoride hollow fibers for recovery of hydrogen and propylene
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DOI：
10.1016/j.jiec.2020.04.031
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发表时间：
2020-05
影响因子：
6.1
通讯作者：
M. A. Abdul Hamid;Hae‐Kwon Jeong
中科院分区：
文献类型：
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作者：
M. A. Abdul Hamid;Hae‐Kwon Jeong
在商业上有吸引力的可伸缩聚合物中空纤维上制备无缺陷的ZIF-8膜是非常可取的，特别是在纤维的内孔一侧，但相当具有挑战性。在此，我们报道了一种在聚偏氟乙烯(PVDF)微滤中空纤维上用二次生长法简便地合成互连良好的ZIF-8膜的方法。强碱表面改性促进了中空纤维高度异质成核，形成了致密堆积的ZIF-8种子层。在连续的生长溶液中二次生长晶种，形成厚度为˜1.2μm的ZIF-8膜，所制备的ZIF-8膜具有高的气体渗透率，对H_2和C_3H_6的透气率分别达到16,344×10−10−m~(-2)s~(-1)和197×10 mol~(-2)m~(-2)s~(-1)。H_2/CH_4、H_2/C_3H_6、H_2/C_3H_8和C_3H_6/C_3H_8气体对的选择性分别为12、57、160和15。我们预计该方法有可能应用于将通常用于水分离的商业PVDF超滤/微滤中空纤维转化为高质量的用于H_2净化和C_3H_6/C_3H_8分离的ZIF-8膜。
It is highly desirable to prepare defect-free ZIF-8 membranes on commercially attractive scalable polymer hollow fibers, especially on the bore side of the fibers, yet quite challenging. Herein, we report a facile synthesis of well-intergrown ZIF-8 membranes on polyvinylidene fluoride (PVDF) microfiltration hollow fibers by a secondary growth method. Surface modification using a strong base promoted high heterogeneous nucleation, resulting in densely packed ZIF-8 seed layers on the hollow fibers. The seed crystals were secondarily grown under a continuous flow of growth solution to form ZIF-8 membranes with thickness of˜1.2 μm. The prepared ZIF-8 membranes achieved high gas permeances, reaching values of 16,344 × 10−10mol m-2s-1Pa-1for H2and 197 × 10−10mol m-2s-1Pa-1for C3H6. The selectivities for H2/CH4, H2/C3H6, H2/C3H8and C3H6/C3H8gas pairs were found to be 12, 57, 160 and 15, respectively. We anticipate that the method could potentially be applied to transform commercial PVDF ultrafiltration/microfiltration hollow fibers commonly used for water separation into high quality ZIF-8 membranes for H2purification and C3H6/C3H8separation.