UiO-66膜的制备及其对正/异丁烷体系的分离

Fabrication of UiO-66 Membrane for the Separation of n-Butane/i-Butane

用擦涂法在α-Al_2O_3支撑体上引入ZrO_2层,利用晶种二次生长法,在α-Al_2O_3支撑体的ZrO_2层上引入UiO-66晶种,成功制备了UiO-66膜。通过XRD和SEM对UiO-66晶种及膜的结构和形貌进行了表征,考察了调节剂乙酸含量和ZrO_2过渡层对UiO-66膜结构和形貌的影响。在温度25℃、压力0.08MPa下,测试了气体分子的渗透性能,检测了UiO-66膜的完整性。考察了跨膜压差和温度对i-C_4H_(10)和n-C_4H_(10)两种气体在UiO-66膜上渗透速率的影响,探究了UiO-66膜对i-C_4H_(10)和n-C_4H_(10)两种气体的渗透选择性能。结果表明,采用多次擦涂法引入ZrO_2层后,获得了覆盖度高且膜层厚度均匀的UiO-66膜,膜厚度为5μm。UiO-66膜对i-C_4H_(10)和n-C_4H_(10)两种气体具有反向渗透性能,在跨膜压差为0.08MPa、温度为25℃时,UiO-66膜对i-C_4H_(10)/n-C_4H_(10)两种气体的理想渗透选择性达3.6,渗透速率分别为4.39×10-7和1.22×10-7 mol/(m2·s·Pa)。

Continuous UiO-66 membrane was fabricated on α-Al2O3 support by pre-coating ZrO2 layer and seeding-secondary-growth method.The structure and morphology of UiO-66 seed crystal and membrane were characterized by XRD and SEM.The effects of acetic acid content and ZrO2 transition layer on the structure and morphology of UiO-66 membrane were investigated.The membrane integrity was examined by testing the permeance for gas molecules under the conditions of temperature 25 ℃ and pressure 0.08 MPa.The effects of trans-membrane differential pressure and operating temperature on the permeance and selectivity of i-C4H10 and n-C4H10 on UiO-66 membrane were investigated.As a result,the ZrO2 layer helped to obtain a continuous uniform UiO-66 membrane with a thickness of 5 μm.The UiO-66 membrane had reverse permeance for i-C4H10 and n-C4H10.This membrane showed high selectivity(3.6) for i-C4H10/n-C4H10 with corresponding permeances of 4.39×10^-7 and 1.22×10^-7 mol/(m^2·s·Pa).