氧化铝凝胶改性聚偏氟乙烯超滤膜的制备与表征

为提高聚偏氟乙烯超滤膜的亲水性,采用Al_2O_3凝胶对有机高分子聚偏氟乙烯膜进行改性,制备Al_2O_3凝胶改性聚偏氟乙烯超滤膜,并与非凝胶化无机纳米Al_2O_3颗粒改性进行对比。考察铸膜液中Al_2O_3凝胶加入量对改性聚偏氟乙烯超滤膜性能和结构的影响。采用扫描电镜、X射线能谱、傅里叶红外光谱和超滤实验等对超滤膜结构和性能进行表征,结果表明,Al_2O_3凝胶加入量1.0 g时,改性超滤膜水通量提高5.48倍;扫描电镜表明,改性超滤膜和未改性超滤膜均为典型的非对称结构,改性超滤膜表面孔数目明显增加,断面微观结构未发生改变;红外光谱及能谱分析表明,Al_2O_3凝胶与高分子聚偏氟乙烯之间为物理共混。Al_2O_3凝胶改性聚偏氟乙烯超滤膜,改善了膜表面亲水性,提高水通量,并保持较大截留率。

Preparation and characterization of Al2O3 gel modified PVDF ultrafiltration membranes

In order to improve the hydrophilia of polyvinylidene fluoride(PVDF) ultrafiltration membrane,organic polymer polyvinylidene fluoride film was modified by alumina gel to obtained PVDF ultrafiltration membrane,and compared with non-gelled inorganic nano-alumina particles modified PVDF ultrafiltration membrane.The effects of inorganic alumina gel addition amounts of casting solution on the properties and structures of modified polyvinylidene fluoride film were investigated.The structure and properties of the films were characterized by means of scanning electron microscopy,energy dispersive X-ray spectroscopy,infrared spectroscopy,ultrafiltration experiments and so on.The results showed that when the addition amount of alumina gel was 1.0 g，the water flux of the modified ultrafiltration membrane increase by 5.48 times.The scanning electron micrographs showed that modified and unmodified ultrafiltration membrane were both typical asymmetric membrane structure,and the number of the pores of modified membrane surface increased significantly,while the cross-sectional microstructure did not change.The results of IR and EDS spectroscopy analysis showed that there existed physical action between inorganic alumina gel and polymer polyvinylidene fluoride.Alumina gel modified PVDF ultrafiltration membrane improved hydrophilia of the membrane surface and membrane flux,and maintained larger retention.