医用PVC表面TiO2-ZnO膜的制备及光催化抗菌性能研究

目的提高医用PVC表面的抗菌性能。方法采用sol-gel法制备ZnO溶胶,以P25(商品TiO_2)悬浮液为掺杂组分,制备了不同TiO_2质量分数(20%、40%、60%、80%)的TiO_2-ZnO复合悬浮液,通过提拉法将ZnO、TiO_2-ZnO、TiO_2悬浮液均匀地涂覆在医用PVC材料表面。采用XRD、SEM等技术考察了复合膜的结构和性能。采用平板菌落计数法测定了不同膜材料对大肠杆菌的光催化杀菌性能和抗细菌粘附性能。结果当TiO_2质量分数为20%时,TiO_2-ZnO薄膜的光催化活性高于ZnO;当TiO_2质量分数为40%、60%、80%时,样品的光催化活性相差不大且都低于ZnO。对ZnO膜和TiO_2-ZnO复合膜的细菌抗粘附性和光催化杀菌性的测试结果表明,ZnO膜和不同TiO_2质量分数的TiO_2-ZnO复合膜都具有一定的抗粘附性和光催化灭菌性。在抗粘附方面,TiO_2质量分数为20%的TiO_2-ZnO复合膜的性能最好,对大肠杆菌的粘附率仅为2.6%,优于ZnO膜和TiO_2膜。在光催化灭菌性方面,在波长为365 nm的紫外光照下,样品对大肠杆菌杀灭能力高低顺序为TiO_2≈20%TiO_2-ZnO80%TiO_2-ZnOZnO。结论涂覆ZnO溶胶和TiO_2悬浮液混合溶胶可以明显提高医用PVC表面的抗细菌粘附性能和光催化灭菌活性,而且当TiO_2质量分数为20%时,TiO_2-ZnO具备最好的抗菌性能。

Preparation and Photocatalytic Antibacterial Properties of TiO2-ZnO Coating of Medical-grade PVC Materials

The work aims to improve antibacterial properties of medical grade PVC surface. ZnO sol wasprepared in sol-gel method, TiO2-ZnO composite suspension of different TiO2mass fraction (20%, 40%, 60% and 80%) was prepared with P25 (commodity TiO2) suspension as doping constituent. ZnO, TiO2-ZnO and TiO2suspensions were coated on medi-cal-grade PVC materials uniformly in pulling method. Structure and properties of the composite film were characterized by vir-tue of XRD and SEM techniques. The photocatalytic antimicrobial activity and bacterial adhesion resistance of different coating materials to Escherichia coli were determined in the method of plate culture count. Photocatalytic activity of theTiO2-ZnO film doped with 20 wt% TiO2 was better than that of ZnO; photocatalytic activity of the samples doped with 40 wt%, 60 wt% and 80 wt% TiO2 was close and lower than that of the pure ZnO. ZnO as well as TiO2-ZnO composite films doped with different mass fractions of TiO2 exhibited certain bacterial adhesion resistance and antimicrobial activity. Among these samples, the sam-ple doped with 20 wt% TiO2 exhibited best bacterial adhesion resistance. The adherent mass fraction of Escherichia coli was only 2.6%, superior to that of ZnO and TiO2 films. Under UV irradiation with wave length of 365 nm, rank of antimicrobial ac-tivity among the samples was TiO2≈20 wt% TiO2>80 wt% TiO2>ZnO. The bacterial adhesion resistance and photocatalytic an-timicrobial activity of medical-grade PVC materials can be enhanced by dip coating with ZnO sol and TiO2 suspension. Besides, TiO2-ZnO doped with 20 wt% TiO2has the best antimicrobial activity.