静电纺丝纤维膜固定化漆酶对水中双酚A的降解性能

采用乳液静电纺丝技术原位固定漆酶,利用扫描电子显微镜(SEM)和激光共聚焦扫描显微镜(LCSM)对载漆酶电纺纤维膜的形貌结构进行表征.载酶电纺纤维呈壳-核结构,平均直径为(650±30)nm,表面有许多纳米级孔道;漆酶被成功包埋固定于纤维内部,且保留了79.8%的酶催化活性.以双酚A(Bisphenol A,BPA)为目标污染物,对比电纺纤维膜固定化漆酶和游离漆酶对BPA的降解性能,考察p H值和温度等因素对BPA降解效率的影响.研究结果表明:在优化条件下,电纺纤维膜固定化漆酶对BPA的降解率达80%左右;与游离漆酶相比,固定化漆酶对p H值和温度均表现出更好的耐受性.这主要是因为漆酶被包埋在纤维内部,纤维的聚合物外壳结构可以保护漆酶,减少外界环境对漆酶的影响,而纤维表面的多孔结构可以为漆酶与BPA的接触反应提供通道.

Degradation of bisphenol A in water by laccase immobilized in electrospun fibrous membranes

In this study, emulsion electrospinning was employed to immobilize laccase in situ. The morphology and structure of laccase-carrying electrospun fibrous membranes (LCEFMs) were characterized by using scanning electron microscopy (SEM) and laser confocal scanning microscopy (LCSM). Results show that the LCEFMs was core-shell structure, with an average diameter of (650±30) nm and many nanoscale channels existed on the surface. Laccase was successfully immobilized in the pore of the fiber, and 79.8% of the catalytic activity was retained. The degradation of Bisphenol A (BPA), as a target pollutant, by LCEFMs and free laccase was compared, and the influence of pH and temperature were investigated. The results show that the degradation efficiency of BPA by LCEFMs could reach 80% under the optimized experimental conditions. Compared to free laccase, immobilized laccase exhibited an improved tolerence to the changes of pH and temperature. This was mainly because laccase was encapsulated inside the fiber, and the polymer shell of the fiber could protect laccase from the change of the external environment. Moreover, the porous structure of the fiber also provided accesses for the contact and reaction of laccase with BPA in water.