摘要
二氧化硅(SiO_(2))膜因其耐高温且孔径可调在分离纯化领域得到了广泛关注,但其表面的无定型结构导致渗透性与选择性相互制约,影响分离效果。以二氧化硅膜为基膜,金属有机框架材料(ZIF-8)对其进行修饰改性,制得 SiO_(2)@ZIF-8 复合膜,探究了 ZIF-8 合成条件、ZIF-8 添加量及原料液温度对复合膜乙醇渗透汽化脱水性能的影响。结果表明:ZIF-8 规则的孔道结构提供了额外的水分子传输通道,复合膜的渗透侧含水率可达 99.5%,渗透通量提高至 9.6 kg/(m~2·h),分离因子为 1 973。采用 Arrhenius 方程对改性前后膜的渗透通量与温度的关系进行拟合,发现复合膜在渗透汽化过程中水分子的表观活化能更高,随着温度升高水通量增加的更快,分离效果更好。SiO_(2)@ZIF-8复合膜有效改善了无定型网状结构的缺陷,在渗透汽化有机溶剂脱水方面具有广阔的应用前景。
Silicon dioxide (SiO_(2)) membrane has attracted much attention in the field of separation and purification due to its high-temperature resistance and adjustable pore size. However, the amorphous structure on the surface leads to the mutual restriction of permeability and selectivity, which affects the results of separation. A SiO_(2)@ZIF-8 composite membrane was prepared with SiO_(2)membrane as abase membrane and modified with metal organic framework material (ZIF-8). The effects of synthesis condition of ZIF-8, addition amount of ZIF-8 and temperature of raw material solution on the dehydration inaqueous ethanol solution mixture under pervaporation conditions were investigated. The results show that the regular channel structure in ZIF-8 can provide additional channels for water molecule transport, the water content on the permeate side of the composite membrane is 99.5 %, the permeate flux increasesto 9.6 kg/(m~2·h) and the separation factor is 1 973. A relationship between membrane permeation flux and temperature follows the Arrhenius equation. The apparent activation energy of water molecules in the composite membrane is higher, and the water flux increases faster with the increase of temperature, indicating a better separation effect. SiO_(2)@ZIF-8 composite membrane can effectively improve the defects of amorphous network structure of silica film, which has a broad application prospect in the dehydration of organic solvent by pervaporation.
作者
吴红丹
孙兆颖
周志辉
刘晓迪
WU Hongdan;SUN Zhaoying;ZHOU Zhihui;LIU Xiaodi(School of Resources and Environmental Engineering,Wuhan University of Science and Technology,Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgical Mineral Resources,Wuhan 430081,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2022年第7期1978-1987,共10页
Journal of The Chinese Ceramic Society
基金
湖北省教育厅科学研究计划指导性项目(B2020019)。
关键词
二氧化硅
金属有机框架材料
复合膜
渗透汽化
乙醇脱水
silicon dioxide
metal organic framework material
composite membrane
pervaporation
ethanol dehydration
