蠕虫状孔道介孔SiO_2的合成及其固定化漆酶的活性

Synthesis of Worm-like Mesoporous Silica and Enzymatic Activity of the Immobilized Laccase

以聚环氧乙烷-聚环氧丙烷-聚环氧乙烷三嵌段共聚物(P123)与离子型助表面活性剂{十六烷基三甲基溴化铵(CTAB)、十二烷基硫酸钠(SDS)或N-肉豆蔻酰-D-丙氨酸(C14-D-A)}为结构导向剂,合成了蠕虫状孔道的介孔SiO2,并在P123/C14-D-A/TMAPS(N-三甲氧基硅丙基-N,N,N-三甲基氯化铵)合成反应体系中,研究了扩孔剂聚乙二醇(PEG)-400的不同添加量对蠕虫状孔道的扩孔效果.合成的产物分别用X-射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和N2吸附进行表征.此外,利用溶剂萃取法对扩孔后的蠕虫状介孔SiO2进行处理,得到不同孔径的季铵盐官能团化介孔SiO2,分别用于漆酶的固定化;并对固定化酶的稳定性、所需的最佳pH值以及降解2,4-DCP的重复利用性进行了研究.通过比较研究发现,介孔SiO2孔径与漆酶分子直径的匹配性是影响固定化漆酶比活及降解2,4-DCP效率的重要因素.

Mesoporous silica with worm-like pore channels was synthesized using mixed P123(polyethyleneoxide-polypropylene oxide-polyethylene oxide triblock copolymer EO20PO70EO20) and ionic cosurfactant {CTAB,SDS or N-myristoyl-D-alanine(C14-D-A)} as a structure-directing agent,and the pore-expanding effect of different amount of PEG-400 on the worm-like pore channels was studied.The synthesized products were characterized using X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and nitrogen sorption analysis.Moreover,the worm-like pore-expanded mesoporous silica was extracted with solvent,and the obtained quaternary ammonium functionalized mesoporous silica with different pore size was applied to immobilize laccase respectively.The stability of immobilized laccase,the optimum pH value acquired and reusability for the degradation of 2,4-DCP were also studied.Through comparative studies,it is found that,matching of sizes between the enzyme molecule and the pore diameter of the mesoporous silica,is essential for specific activity of immobilized laccase and degradation efficiency of 2,4-DCP by immobilized laccase.