等离子体引发自由基增强光催化降解医用PVC的研究

Research on Enhanced Photocatalytic Degradation of Medical PVC by Plasma-initiated Free Radicals

研究了等离子体引发的自由基对锐钛矿TiO2光催化降解医用聚氯乙烯(PVC)的影响.等离子体改性前后PVC的表面特性通过接触角、表面张力、X-光电子能谱(XPS)、电子自旋共振(ESR)表征.结果表明,等离子体改性后PVC的表面自由能和润湿性增强,水、丙三醇、硫代双乙醇的接触角减小.ESR表明等离子体改性后PVC表面的自由基增加了10倍.此外,通过重量损失和扫描电镜(SEM)对比了PVC-TiO2和等离子体改性PVC-TiO2的光催化降解,紫外光照60 h后,等离子体改性PVC-TiO2的失重率比PVC-TiO2增加了27.4%,SEM显示光照后等离子体改性PVC-TiO2的表面有大量的裂纹.等离子体改性后PVC的光催化降解加剧.

Effects of plasma-initiated free radicals on photoeatalytic degradation of medical PVC with anatase TiO2 were studied. Surface properties of PVC were characterized by the contact angle, surface tension, X-ray photoelectron spectroscopy （XPS） and electron spin resonance （ESR）. The results indicate that the surface free energy and wettability of plasma-treated PVC increase greatly. The contact angles of distilled water, glycerin and dihydroxyethylsulfide for the plasma-treated PVC decrease. ESR reveals radicals on the surface of the plasma-treated PVC film nearly increase ten times. Moreover, the photodegradation of the PVC-TiO2 was compared with that of plasma-treated PVC- TiO2 through performing weight loss monitoring, scanning electron microscopic （SEM） analysis. Weight-loss rate of the plasma-treated PVC- TiO2 increases 27.4% in comparison with that of PVC-TiO2 under UV irradiation for 60 hours. SEM of the plasma-treated PVC-TiO2 film shows a lot of crack on the surface after photodegradation. Plasma treatments aggravate the photocatalytic degradation of medical PVC.