纳米粒子/氧化石墨烯改性复合膜制备及其分离性能研究

Preparation and separation performance of nanoparticles/graphene oxide modified composite membrane

采用真空抽滤-压力喷涂的方法,以聚酰胺纳滤膜为基膜,制备了氧化石墨烯和二氧化钛纳米粒子质量比为1∶1、2∶1、3∶1和4∶1的复合膜GOT1、GOT2、GOT3和GOT4以及氧化石墨烯和二氧化硅纳米粒子质量比为1∶1、2∶1、3∶1和4∶1的复合膜GOS1、GOS2、GOS3和GOS4。通过SEM、EDS、XPS和GIWAXS方法对GOT复合膜和GOS复合膜进行了分析表征,结果表明,氧化石墨烯和纳米粒子均匀负载在聚酰胺纳滤膜表面。研究了复合膜的性能,并推测了复合膜的净水机理。其中GOT复合膜在0.75 MPa下水通量可达50 L·m^(-2)·h^(-1),相较于原始基膜提高了25%,显示出了最佳的水通量性能,并且在保持较高通量的同时,对盐溶液和重金属离子的截留率仍能维持在90%左右。真空抽滤-压力喷涂的方法为氧化石墨烯复合膜的制备提供一种新的工艺思路,为废水处理提供了一种更高净化效率的复合膜。

On the surface of polyamide nanofiltration membranes(NF),two nanoparticle intercalated graphene oxide composite membranes were loaded through the method of vacuum extraction filtration and pressure spraying.The mass ratio of graphene oxide(GO)and silicon dioxide(SiO2)for the composite membranes GOS1,GOS2,GOS3,GOS4 were 1∶1,2∶1,3∶1,4∶1.The mass ratio of graphene oxide(GO)and titanium dioxide(TiO2)for the composite membranes GOT1,GOT2,GOT3,GOT4 were 1∶1,2∶1,3∶1,4∶1.GOT and GOS composite membranes were characterized by SEM,EDS,XPS and GIWAXS.The results indicated that GO and nanoparticles were uniformly loaded on the surface of polyamide nanofiltration membrane.The properties of the composite membranes were studied,and the water purification mechanism of the composite membranes was speculated.The water flux of GOT composite membrane can reach 50 L·m^(-2)·h^(-1) at 0.75 MPa,which is 25%higher than that of the original substrate.The GOT composite membrane has the higher flux and maintain a higher flux compared with the original base membrane.At the same time,it can maintain a rejection rate of about 90%for salt solution and heavy metal ions.This topic provides a new process idea for the preparation of graphene oxide composite membranes and a composite membrane with higher purification efficiency for wastewater treatment.