超支化聚合物PAMAM表面改性PAN超滤膜

Surface Modification of PAN Ultrafiltration Membrane with Hyperbranched Polymer PAMAM

首先通过碱处理将聚丙烯腈(PAN)超滤膜表面的氰基转变为羧基,然后使其在聚酰胺-胺(PAMAM)水溶液中与PAMAM进行表面改性反应,制得PAN-PAMAM膜。采用傅里叶红外光谱(FT-IR)、X光电子能谱(XPS)、扫描电镜(SEM)和原子力显微镜(AFM)等手段对PANPAMAM膜的结构进行表征。结果表明:通过表面改性反应,PAMAM结合在PAN超滤膜表面,形成一层致密、光滑的亲水性表层;PAN-PAMAM膜的接触角比纯PAN超滤膜降低了20°左右;PAN-PAMAM膜的纯水通量为14.9L/(m^2·h),对聚乙二醇(PEG2000)的截留率达到91.4%。

Polyacrylonitrile(PAN)ultrafiltration membrane modified with hyperbranched polymer polyamide-amine(PAMAM)was investigated in detail.First,PAN membrane was treated with the alkali solution to produce carboxyl groups on its surface.Then,PAMAM solution was used to react with the hydrolyzed PAN membrane at different temperatures to prepare PAN-PAMAM membranes.The obtained membranes were characterized by Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM)and atomic force microscopy(AFM).FT-IR spectra and XPS results proved that PAMAM molecules were immobilized onto the surface of PAN-PAMAM membrane by the condensation reaction between-COOH groups of hydrolyzed PAN and-NH2 groups of PAMAM.SEM images revealed that a new dense and smooth layer was formed on the surface of PAN-PAMAM membrane,which was composed of PAMAM.Moreover,both the morphology and the thickness of the layer changed with the reaction temperature.AFM images further revealed that the surface roughness of the membrane decreased obviously after modification.For PAN-PAMAM membrane prepared at 80℃,the water contact angle declined by 20°compared with the original PAN membrane.PAN-PAMAM membrane showed a decreased water flux and an increased retention rate after modification.PAN-PAMAM membrane showed a water flux of 14.9 L/(m^2·h),and its retention rate of PEG2000 reached 91.4%.