左氧氟沙星共混PVDF抑菌超滤膜的制备及性能表征

Preparation and characterization of levofloxacin/polyvinylidene difluoride blend ultrafiltration membrane with antibacterial property

采用浸没沉淀相转化法制备了左氧氟沙星(LVFX)共混聚偏氟乙烯(PVDF)超滤膜,考察了左氧氟沙星作为添加剂对膜结构及性能的影响.采用傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)和接触角等表征手段,分析了左氧氟沙星在PVDF膜上存在及其对膜结构和亲水性能的影响规律.分别利用牛血清蛋白(BSA)静态吸附、循环通量衰减和抑菌圈、抑菌率评价了LVFX/PVDF共混膜的抗污染性能和抑菌性能.结果表明,左氧氟沙星稳定存在于膜上;随着左氧氟沙星添加质量分数的增加,共混膜的接触角由77.7°下降至62.1°,亲水性增强;共混膜的BSA静态吸附量下降,通量恢复率升高,不可逆污染指数在LVFX添加质量分数为0.6%时,降至11.8%,抗污染能力最佳;LVFX添加质量分数为0.3%时,即有抑菌圈生成,添加质量分数为0.6%时,抑菌率可达92.3%,抑菌性能优异.此外,一段时间运行的共混膜经再生后,仍能保持较好的抑菌效果.

Levofloxacin(LVFX)/polyvinylidene difluoride(PVDF)blend ultrafiltration membrane was prepared by immersion-precipitation phase inversion method.The effects of levofloxacin as additive on membrane structure and properties were investigated.Fourier transform infrared spectroscopy(FTIR)、scanning electron microscope(SEM)and contact angle were used to characterize the existence of levofloxacin on PVDF membrane and its influence on membrane morphology and hydrophilicity.The antifouling performance and antimicrobial activity of LVFX/PVDF blend membrane were evaluated respectively by static adsorption of BSA,decay of circulating flux,inhibition zone and inhibition rate.The results showed that levofloxacin was present on the membrane stably.With the increase of the levofloxacin ratio,the contact angle of the blend membrane decreased from 77.7°to 62.1°,the hydrophilicity of the membrane was enhanced.The BSA static adsorption capacity decreased while the flux recovery rate increased,the irreversible pollution index decreased to 11.8%when the addition mass fraction of LVFX was 0.6%,which possessed the best antifouling ability.The inhibition zone was formed when the addition mass fraction of LVFX was 0.3%.When the adding mass fraction was 0.6%,the antibacterial rate could reach 92.3%,showing excellent antibacterial properties.In addition,the blend membranes were regenerated after run for a period of time,still maintained a good antibacterial effect.