摘要
基于金属有机框架(MOFs)的柔性复合膜材料在气体分离、污染物吸附、药物可控释放等领域具有重要的作用。利用同轴静电纺丝技术,在聚偏氟乙烯(PVDF)的高分子溶液中添加有机配体2-甲基咪唑(2-mI)作为外壳纺丝液,在甘油中添加锌离子作为内芯纺丝液,制备得到的核壳结构纳米纤维进行水热反应。在内芯甘油溶解形成中空结构的同时,锌离子向外扩散接触到外壳高分子层内表面的有机配体,在中空纳米纤维(HNFs)内部原位生成了MOF晶体ZIF-8,得到了ZIF-8@HNFs柔性复合膜材料。同时研究了金属盐与有机配体的不同比例、水热生长时间和温度对中空纳米纤维内部生长ZIF-8的影响。最佳金属盐与有机配体的摩尔比为1∶40,65℃水热生长4 h。采用XRD、SEM、FTIR、TGA和氮气吸附-脱附实验等对ZIF-8@HNFs柔性复合膜的结构和性能进行了表征。结果表明:ZIF-8原位生长在中空纳米纤维内部,负载量为3.351wt%,ZIF-8@HNFs复合材料的比表面积为38.189 m^(2)/g、孔体积为0.204 cm^(3)/g、孔径分布在4.678 nm和7.573 nm,并且可以耐受200℃高温、多次弯折和纯水、碱液的浸泡4 h依旧保持结构的稳定性。而ZIF-8本身在酸性条件下会发生解离的特性,使得ZIF-8@HNFs柔性复合膜材料在污染物吸附-解吸、药物可控释放等领域具有潜在的应用价值。
The flexible composite membranes materials based on metal organic frameworks(MOFs)play a significant role in many fields such as gas separation,pollutant removal and controlled drug release system.Utilizing coaxial electrospinning technology,the composite nanofibers of core-shell structure was prepared by mixing organic ligand 2-methylimidazole(2-mI)in polyvinylidene fluoride(PVDF)polymer solution as shell spinning solution,and adding zinc ion to glycerol as core spinning solution.With hydrothermal synthesis,the glycerol in the core layer dissolves to form a hollow structure,while the zinc ion diffuses outward and contacts the organic ligands on the inner surface of the polymer shell layer at the same time.The in-situ growth of ZIF-8 MOF crystals inside PVDF hollow nanofibers(HNFs)were obtained as the ZIF-8@HNFs flexible composite membrane material.The effect of different metal salt and ligand proportions,different hydrothermal growth time and temperature on the formation of ZIF-8 in HNFs were studied.The molar ratio of zinc ion and 2-mI ligand was 1∶40,and the hydrothermal growth condition was at 65℃for 4 h with water as solvent,which proved to be the optimal preparation circumstance.The structure and performance of ZIF-8@HNFs were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),thermogravimetry analysis(TGA)and the nitrogen adsorption-desorption test,etc.The results indicated that the ZIF-8 crystals were in-situ synthesized and loaded inside the PVDF HNFs with 3.351%content.The Brunner-Emmet-Teller measurements(BET)surface area was 38.189 m^(2)/g,the pore volume was 0.204 cm^(3)/g and the pore size distribution were at 4.678 nm and 7.573 nm.Furthermore,the ZIF-8@HNFs still maintains its structural stability after being treated with 200℃high temperature,multiple bending and soaking with water or alkali solution for 4 h.The characteristic of ZIF-8 that itself can dissociate under acidic conditions,which makes the ZIF-8@HNFs flexible composite membrane material potentially valuable in areas such as contaminant adsorption-desorption and controlled drug release system.
作者
郑凯
周全
杨帆
任瑞鹏
吕永康
ZHENG Kai;ZHOU Quan;YANG Fan;REN Ruipeng;LYU Yongkang(State Key Laboratory of Clean and Efficient Coal Utilization,College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《复合材料学报》
北大核心
2025年第3期1622-1632,共11页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(21707098)。
