氟化聚醚砜疏水膜的制备及其膜蒸馏应用

Preparation of fluorinated polyethersulfone hydrophobic membrane and its application in membrane distillation

以全氟辛基乙基甲基丙烯酸酯(FMA-C8)为接枝单体,采用溶液均相共辐照方式(^(60)Coγ射线)对聚醚砜(PES)材料进行疏水改性,制备得到氟化的PES(PES-g-PFMA-C_(8)),进而将其喷涂在自制多孔PES膜表面制备得到疏水化的PES膜.借助红外光谱、光电子能谱、接触角仪等对PES-g-PFMA-C_(8)及其改性膜进行表征,探究喷涂疏水改性对PES膜性能的影响.结果表明,疏水改性PES膜(H-PES)的疏水性较PES膜显著提高,接触角由73.1°增大到109.3°,液体进入压力由295 kPa提高到410 kPa,70℃下对质量分数3.5%NaCl盐溶液进行真空膜蒸馏时,80 h长时间运行过程中通量保持在50 kg/(m^(2)·h)左右,脱盐率高达99.98%;且该膜应用于海水淡化反渗透浓水处理过程中,产水水质稳定,能将海水淡化的总体水回收率由45%提高到83.7%,在膜蒸馏脱盐方面具有较好的应用潜力.

1H,1H,2H,2H-perfluorodecyl methacrylate(FMA-C_(8))was used as monomer,and grafted onto polyethersulfone(PES)by simultaneous irradiation in a homogeneous system under^(60)Coγ ray.The grafted product PES-g-PFMA-C8 with high hydrophobicity was obtained.PES-g-PFMA-C_(8)was then sprayed onto home-made porous PES membranes to fabricate hydrophobic PES membranes(H-PES).The effects of spraying on PES membranes were investigated via Fourier transformed infrared spectroscopy,X-ray photo electronic spectroscopy and optical contact angle goniometer,etc.The results showed that the hydrophobicity of H-PES membrane increased obvisouly after spraying modification:contact angle increased from 73.1°to 109.3°,and liquid entry pressure increased from 295 kPa to 410 kPa.During an intermittent 80 h VMD desalination operation,a flux of approximately 50 kg/(m^(2)·h)and a stable salt rejection of 99.98% were achieved when a 3.5%NaCl solution was treated at 70℃ by the H-PES membrane.Furthermore,the H-PES membrane was applied to concentrate RO brines,and the permeate quality was high,and the water recovery increased from 45% to 83.7%,showing great potential in the real application of membrane distillation desalination.