Studies Of MCM-41Preparation And Its Application In Lipase Immobilization

In this research, plenty of attention was paid to the synthesis of MCM-41and itsapplication in lipase immobilization. The monodisperse and regular MCM-41wasprepared and used to study the relationship between the surface properties of supportsand the performance of lipase.Firstly, polyvinyl alcohol was introduced to synthesize monodisperse MCM-41nanospheres. Two samples were obtained through two-stage centrifugation, and theparticle size of them were100nm~300nm via centrifugation at12000rpm and400nm~700nm at4200rpm, respectively. No matter what the size is, the samplesmaintain high specific surface area more than1100m2·g-1and large pore size over2.0nm. The synthetic materials were perfectly spherical in shape and can disperse inwater stably for a long time without coagulation. Furthermore, the particle size can becontrolled by adjusting the synthesis case. The sample with uniform particle sizewhich is about500nm was obtained when the amount of TEOS is0.75mL.Secondly, the comparison was carried out between4200-PVA-MCM-41andMCM-41in lipase immobilization to study the relationship between the morphologyof the supports and the activity and stability of lipase. The adsorption kinetic,adsorption isotherm, thermal stability, reuse stability and storage stability werestudied. The results showed that the stability of lipase immobilized on4200-PVA-MCM-41was much higher than that immobilized on MCM-41. However,its activity is just around50%of the lipase on MCM-41.Lastly, the influence of the functional group on the lipase properties was studied.4200-PVA-MCM-41and MCM-41were modified with different carbon chain, andthe adsorption amount, activity and stability of the lipase were discussed. The resultsshowed that the stability and activity of lipase improved with the increase of carbonchain. The lipase on modified4200-PVA-MCM-41showed higher stability andactivity and the highest stability and activity was awarded to the lipase immobilizedon4200-PVA-MCM-41modified by cetyl.Furthermore, this research studied the synthesis mechanism of MCM-41.Meanwhile, the phenomena in the experiments were explained properly.