SiO_2及Ag^+-SiO_2填充PEBAX/PAN复合膜渗透汽化分离噻吩

Separation of thiophene by using SiO_2 and Ag^+-SiO_2 filled polyether block amide(PEBAX)composited membranes via pervaporation

采用经典Stber方法制备了微米固体SiO2(μ-SiO2)及Ag+修饰SiO2颗粒(Ag+-SiO2).以纳米气相SiO2(n-SiO2)、μ-SiO2以及Ag+-SiO2为填充物,分别制备了PEBAX/PAN复合膜及三种填充型复合膜.XRD、FTIR分别考察了修饰前后颗粒的晶体结构情况及成分,SEM表征了Ag+-SiO2及膜的形貌结构.另外,还研究考察了膜在噻吩/正庚烷溶液中的溶胀情况,结果显示:随料液噻吩含量的增加溶胀度增大,膜溶胀度大小顺序为:Ag+-SiO2填充型复合膜(PMSA)>n-SiO2填充型复合膜(PMS1)>μ-SiO2填充型复合膜(PMS2)>复合膜(PM).渗透汽化实验考查了上述四种膜分离噻吩能力,结果表明:三种填充型复合膜分离因子得到提高,但渗透通量有所降低,其中PMSA分离性能最佳.在填充量为5%、温度为30℃,料液噻吩质量分数为1×10-3时,PMSA的分离因子为4.2,渗透通量为2.8kg/(m2·h).

Silica microspheres and silver/silica core-shell microspheres were prepared by the method of Stober. Composite membrane of polyether block amide /polyacrylonitrile （PEBAX/PAN） and mixed matrix membranes with nano-fumed silica, silica microspheres and Ag^＋- SiO2 core shell microspheres as the filler, were prepared. The formation and composition of the particles before and after modified were characterized by XRD and FTIR, respectively. The structure morphology of Ag^＋ - SiO2 core shell microspheres and the membranes were respectively characterized by SEM. In addition, swelling situation of membranes was explored. The experimental results display that the swelling degree of the membranes in model gasoline with thiophene and n-heptane increases with thiophene content. The swelling degree of the membranes as follows. Ag^＋ - SiO2 filled membrane（PMSA） 〉 nano- fumed silica filled membrane（PMS1） silica microspheres（PMS2）〉 composite membrane（PM）. The separation abilities to thiophene of four membranes were systematically investigated by pervaporation experiments. The experimental results showed that separation factor of all the three filled-composite membranes was intensified, but their fluxes decreased slightly. It also exhibited the PMSA has the best separation performance, its separation factor and the total flux were 4.2 and 2. 8 kg/（m2 · h） respectively, under the thiophene mass fraction 1× 10^-3 at 30℃.