SiO2-PEBAX／PAN膜渗透汽化分离吡啶

Pervaporation Separation of Pyridine Using SiO_2 Filled Polyether Block Amide(PEBAX) Membranes

以聚醚共聚酰胺(PEBAX)为分离膜材料,聚内烯腈(PAN)超滤膜为支撑层,纳米气相二氧化硅(n-Si O2)颗粒为填充物,分别制备了PEBAX/PAN复合膜及n-Si O2-PEBAX/PAN填充型复合膜,旨在通过渗透汽化分离吡啶。采用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)对复合膜进行表征,表明n-Si O2与聚合物只是物理混合。以吡啶/正庚烷混合物为模拟溶液,考察膜的溶胀及渗透汽化分离性能。溶胀实验结果表明:膜溶胀度随料液吡啶含量及温度的增加而增大。渗透汽化实验结果表明:n-Si O2填充量为10‰(wt)时总渗透通量最大,填充量为5‰(wt)时分离因子最大。总渗透通量和分离因子都随料液吡啶浓度增大而增加;渗透汽化操作温度升高,总渗透通量增大,而分离因子减小。当填充量为5‰(wt)、温度为30℃、以及料液吡啶含量为5000?g?g?1时,Pn5膜的总渗透通量为5.05 kg?m?2?h?1,分离因子为3.39。研究结果表明,Si O2-PEBAX/PAN复合膜对吡啶有较好的富集作用。

Polyether block amide/polyacrylonitrile （PEBAX/PAN） and nano-fumed silica filled PEBAX/PAN composite membranes were prepared for pyridine separation via pervaporation. The membranes were characterized by SEM, XRD and FT-IR, and the results indicate that n-SiO2 is physically blended with polymer. Swelling property and pervaporation performance were explored using model gasoline composed of pyridine and n-heptane. Swelling results show that the degree of swelling in model gasoline （pyridine and n-heptane） increases with pyridine concentration and temperature. The membrane with 10 %o（Wt） nano-fumed silica exhibits better total permeation flux, while the membrane with 5%o（wt） nano fumed silica shows better separation factor. Both total permeation flux and separation factor increase with the increase of pyridine concentration in the feed, while feed temperature increase enhances permeation flux but weakens separation factor. When the pyridine concentration is 5000 μg.g^-1 at 30℃, the total permeation flux and separation factor of the membrane with 5‰（wt） nano-fumed silica are 5.05 kg.m^-2.h^-1 and 3.39, respectively. The results indicate that the silica filled PEBAX/PAN membrane is efficient in pyridine enrichment.