硬脂酸改性γ-Al_2O_3填充PEBAX膜渗透汽化分离苯胺

Aniline Separation via Pervaporation Using PEBAX Membranes Filled with Stearic Acid Modified γ-Al_2O_3

利用硬脂酸对纳米γ-Al_2O_3改性,分别制备了聚醚共聚酰胺(PEBAX)均质膜、填充膜、复合膜以及填充型复合膜四种分离膜,探讨了膜在苯胺/正庚烷体系中的溶胀性能和渗透汽化性能。利用FT-IR、XRD分别考察了改性前后γ-Al_2O_3颗粒官能团和晶体结构的变化情况,通过SEM观察膜的形貌结构。溶胀实验结果表明:随着料液中苯胺浓度和料液温度的升高,溶胀度均持续增大,在48 h时达到溶胀平衡,填充量为2%(wt)时填充膜的溶胀效果最好;渗透汽化实验结果表明:膜的渗透通量和分离因子均随料液中苯胺浓度和料液温度的升高而持续增大,填充型复合膜的综合性能最优,其填充量为2%(wt)时分离性能最佳,当苯胺浓度为5000μg×g^(-1)、温度为70℃时,膜的渗透总通量为5.64 kg×m^(-2)×h^(-1),分离因子为3.07。

Stearic acid modified nanoγ-Al2O3 was used to prepare different polyether co-polyamide(PEBAX)membranes(homogeneous membrane,filled membrane,composite membrane and composite-filled membrane).Swelling and pervaporation performance of the membranes in aniline/n-heptane were studied.The functional groups and crystal structure ofγ-Al2O3 particles before and after modification were investigated by FT-IR and XRD,respectively.Morphology of the membranes was characterized by SEM.Swelling results show that swelling degree increases with the increase of aniline concentration and liquid temperature,and it reaches equilibrium after 48 h.Moreover,effects of filler contents on swelling performance was studied and swelling degree reaches maximum for the membrane with 2%(wt)filler.Pervaporation results reveal that both the permeation flux and separation factor increase constantly with the increase of aniline concentration and temperature,and the composite-filled membrane with 2%(wt)modifiedγ-Al2O3 shows the best separation performance.When the aniline concentration is 5000μg·g-1 and feed temperature is 70℃,the total permeation flux and separation factor of the membrane are 5.64 kg·m-2·h-1 and 3.07,respectively.