Preparation of ZIF-8@PEBAX/PVDF nanocomposite membrane by the combination of self-assembly and in-situ growth for removing thiophene from the model gasoline

Metal-organic frameworks(MOFs)have gained attention in the development of MOFs/polymer hybrid membranes for pervaporation.However,the agglomeration of MOFs particles and interfacial defects limit its further application.In this study,we present a novel approach to fabricate a ZIF-8@PEBAX/PVDF nanocomposite membrane for removing thiophene from the model gasoline by combination of selfassembly and in-situ growth.Firstly,a PVDF supporting membrane was modified to have a negative charge.Next,positively charged zinc ions were attracted onto the negatively charged PVDF supporting membrane through electrostatic interaction.Afterwards,the Zinc ions deposited PVDF membrane was immersed into dimethylimidazole solution to form a uniform ZIF-8 layer.Finally,the ZIF-8 layer was coated with poly(ether-block-amide)(PEBAX)using the pouring method.Experimental results showed that the separating efficiency of the ZIF-8@PEBAX/PVDF nanocomposite membrane was improved significantly compared to that of pristine PEBAX membrane.The optimal permeation flux and enrichment factor of membrane were 27.80 kg(m^(2)h)^(-1)and 6.9,respectively.

超支化有机硅-酚醛复合材料的制备与性能

设计合成了一种环氧基超支化有机硅树脂(HPSi),将其与酚醛树脂按照不同比例进行混合改性。研究结果表明,固化后材料的耐烧蚀性能、力学性能及耐湿性有了明显提升,当HPSi的质量分数为酚醛树脂的20%时,800℃在空气及氮气中的残碳率分别为24.2%和65.1%,而原酚醛树脂仅为3.0%和61.9%;改性后冲击强度为4.88 kJ/m^(2)、吸水率为1.0%,分别提升了400%和52%。同时环氧基超支化有机硅树脂与酚醛树脂显示出良好的相容性,改性后的酚醛树脂的介电性能显著提高,该项工作有望在航空航天科学和工业领域实现新的应用。