聚醚砜微孔膜的疏水改性及其在膜蒸馏中的应用

Application of hydrophobically modified polyethersulfone membranes in membrane distillation

以全氟正已烷为等离子体源对聚醚砜微孔膜进行表面疏水改性,X光电子能谱(XPS)分析结果证实了全氟正己烷在膜表面的存在,膜表面氟含量最高达到49%。改性后的膜疏水性显著提高,水接触角从92°提高到123°。扫描电镜结果显示改性膜的表面被一薄层覆盖,但膜的本体结构无明显变化。将改性后的膜用于真空膜蒸馏淡化模拟海水的试验中,结果表明在雷诺数较小的情况下,改性膜的脱盐率达99．99%,通量迭4530ml/(m^2·h)。

The hydrophobic surface modification of polyethersulfone microporous membranes was achieved via low temperature perfluohexane plasma treatment. X-ray photoelectronic spectroscopy （XPS） results confirmed the existence of perfluohexane segments on the membrane surfaces and the content of fluorin reached 49%. Water contact angle of the membranes increased from 92 to 123°, suggesting the hydrophobicity of the membranes was improved significantly. Furthermore, scanning electronic microscopy （SEM） images showed that the surface of the modified membrane was covered by a lamella which contained fluorin, but the main structure was not changed. The modified membranes were applied in vacuum membrane distillation （VMD） for desalination. The experimental results showed that, under a low Re constant, the desalination rate was 99.99% and the distillation flux reached 4530ml/（m^2· h）.