P(GMA-co-HEMA)/SiO_2大孔复合材料的制备及其在固定化脂肪酶中的应用

Preparation of P(GMA-co-HEMA)/SiO_2 macroporous composite and its application in lipase immobilization

以块体SiO2大孔材料为基质,甲基丙烯酸缩水甘油酯(GMA)和甲基丙烯酸羟乙酯(HEMA)为功能单体,通过原位聚合和溶剂蒸发制备P(GMA-co-HEMA)/SiO2大孔复合材料,用SEM、EDS、BET、FTIR和TGDTA对样品进行表征,并将其用于固定褶皱假丝酵母脂肪酶(CRL)。结果表明:SiO2大孔材料很强的毛细管作用使共聚物均匀地涂敷在其孔壁上,形成P(GMA-co-HEMA)/SiO2复合纳米薄膜。共聚物的负载量和亲疏水性可分别通过改变单体浓度和体积比进行调控,当单体体积浓度为10%、GMA和HEMA的体积比为9∶1时大孔复合材料固定化脂肪酶比酶活达到最高,为3 886.9U/g,与底物反应重复操作8批次后剩余酶活率为68.7%。

A P（GMA-co-HEMA）/SiO2 macroporous composite was synthesized by in-situ polymerization followed by solvent evaporation via a large-sized macroporous SiO2 material as substrate and glycidyl methacrylate（GMA）,2-hydroxyethyl methacrylate（HEMA）as the functional monomers.Samples were characterized by SEM,EDS,BET,FTIR and TG-DTA.The P（GMA-co-HEMA）/SiO2 macroporous composite was employed as support for the immobilization of lipase from Candida rugose（CRL）.The results show that the strong capillarity effect of the macroporous SiO2 material makes the copolymer coating on its pore wall uniformly,forming the P（GMA-co-HEMA）/SiO2 composite nano-film.The loading amount and the hydrophilicity of the copolymer can be adjusted by changing the concentration of the monomers and the volume ratio of the monomers,respectively.When the volume concentration of monomers is 10% and the volume ratio of GMA to HEMA is 9∶1,the immobilized lipase reaches its highest specific activity of 3 886.9U/g and remains 68.7% of its initial activity after 8consecutive batches of reaction with the substrate.