纳米纤维膜固定化酶及酶-膜反应器的构建和性能的研究.pdf

浙江大学硕士学位论文摘要酶一膜反应器将酶的催化功能与膜的分离功能交叉融合,以创造出有利的过程热力学和动力学,在降低成本的同时极大地提高了反应效率,因而在化学化工的诸多领域中得到越来越广泛的应用。固定化酶活性以及反应器构造对酶一膜反应器效率有着重大影响。本论文旨在探索纤维素纳米纤维膜表面固定化脂肪酶的方法,以期获得经济、高效的固定化酶膜,构建并优化固定化酶催化/分离系统。具体内容如下:. 利用静电纺丝法制备了醋酸纤维素纳米纤维膜,研究了纺丝条件对纤维形态和直径的影响,得到最佳纺丝条件。将所得醋酸纤维素膜水解制成再生纤维素纳米纤维膜,并通过场发射扫描电镜(FESEM)、衰减全反射傅里叶红外光谱()以及酸碱滴定方法进行表征。结果表明,水解以后纤维膜中乙酸结合度大幅下降。通过高碘酸钠氧化法氧化再生纤维素纳米纤维膜表面羟基,在膜表面引入醛基,进而与四乙烯五胺反应引入间隔臂,最后通过戊二醛法将脂肪酶固定于再生纤维素纳米纤维膜上。采用响应曲面法(RsM)系统地研究了固定化条件对固定化酶活性的影响,并探讨固定化前后脂肪酶稳定性的变化。最佳固定化条件下,%,同时稳定性也较自由酶有明显提高。在以上工作的基础上,初步探讨了固定化酶膜在生物反应器中的应用。将固定化酶膜应用于两相酶一膜反应器中,以橄榄油水解为模型反应,分别从萃取相的选择、pH、促进剂浓度、温度以及酶膜用量等方面考察了反应器操作条件对水解反应效率的影响。研究表明,在最佳水解条件下,,为这类酶一膜生物反应器的进一步应用提供了参考。差鳝觑醋酸纤维素;电纺纤维膜;脂肪酶;酶固定化;两相酶一膜生物反应器 ABSTRACT Abstract Enzyme—immobilized membrane bioreactors(EMBR)can create afavorable thermodynamics and ics process bining thehi曲selectivity of enzymatic reaction and high efficiency ofmembrane separation,which provide 11igh reaction rate蕊well as low operation cost,and therefore have been widely applied innumerous fieldsoffood,pharmaceutical,and detergent activity ofimmobilized enzyme and the reactor structure play asignificant rolein theperformance these,in thisthesis,cellulose fibrous membrane Wasused硒enzyme-immobilized support toimprove theproperties of immobilized ,a biphasic EMBR based on the lipase- immobilized fibrous membrane Was designed and relative experiments and resultsaresummarized嬲follow. Cellulose acetate(CA)nonwoven fibrousmembrane was prepared by electrospinning,followed by alkalinehydrolysis to obtain regenerated cellulose (RC)nonwoven conditions were systematically and chemistry of the membrane during the deacetylation process were monitored、析廿l fieldemission electron microscopy (FESEM),attenuated total reflectance flouriertransform infrared spectroscopy (ATR/FT-IR)and Was found thatthedeac