远程氩等离子体对聚醚砜膜表面性能的改性

采用双悬浮探针和电子自旋共振法定量对远程氩等离子体进行诊断，确定了电子、离子浓度和自由基浓度的分布，以预测表面改性的最佳区；利用远程氩等离子体对聚醚砜（PES）超滤膜进行表面改性，通过接触角测量、扫描电子显微镜和X射线光电子能谱分析改性前后膜表面结构和性能的变化，最后利用牛血清蛋白分离实验分析改性前后膜的分离性能和抗污染性能变化.结果表明，氩等离子体中电子、离子浓度沿轴向距离逐渐降低，在30cm后接近于0，而40cm处自由基浓度仍维持在90%以上，为可能的最佳表面改性区；在该区对PES超滤膜改性后，引入含氧基团和含氮基团，膜表面（O+N）/C原子比从0.18增大到0.46，增强膜表面极性；在最佳处理条件下，膜表面接触角从67°减小到18°，使膜表面亲水性能增强，抑制了电子、离子对膜的刻蚀作用；通过牛血清蛋白实验测定改性后膜污染率由70.3%减小到64.7%，抗污染性能提高.

Surface properties modification of polyethersulfone membrane by remote argon plasma

In this paper, the concentration distribution of electrons, ions and free radicals in remote argon plasma was studied by using double suspension probe and electron spin resonance method to predict the optimal surface modification region. Then, PES membranes were placed in this region and modified by remote argon plasma. Water contact angle measurement, X-ray photoelectron spectroscopy and scanning electron microscope were used to characterize the surface structure and properties of PES membranes. Finally, the separation performance and anti-pollution performance of membranes before and after modification were analysed in bovine serum albumin separation experiment. The results showed the electron and ion concentrations in the argon plasma gradually decrease along the axial distance, close to 0 after 30cm, and the free radical concentration at 40cm still remains above 90%, which was the best possible surface modification region. In the remote region, oxygen-containing groups and nitrogen-containing groups were introduced in PES membranes surface, and the (O+N)/C atomic ratio of the membrane was increased from 0.18 to 0.46 to enhance the surface polarity of the membrane. The modified PES membranes in remote region obtained a higher hydrophilicity and the etching by electron and ions on PES membrane surface was prohibited. Under optimal processing conditions, the contact angle decreases from 67° to 18° and the membrane fouling rate after modification reduces from 70.3% to 64.7%.