摘要
In this paper, Fe 3 O 4 nanoparticles coated with mesoporous silica were prepared successfully, noted as Fe 3 O 4 at the mobile composition of matter No. 41 (MCM-41). Also, Fe 3 O 4 at MCM-41 was grafted by both 3-aminopropyltriethoxysilane (APTS) and 3-chloropropyltriethoxysilane (CPS), noted as Fe 3 O 4 at MCM-41/APTS and Fe 3 O 4 at MCM-41/CPS. The compounds were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetry and N 2 adsorption/desorption. Then, the enzyme, porcine pancreas lipase (PPL), was immobilized onto these modified nanoparticles by covalent attachment, physical adsorption and cross-linking, noted as Fe 3 O 4 at MCM-41/CPS-PPL, Fe 3 O 4 at MCM-41-PPL and Fe 3 O 4 at MCM-41/APTS-PPL, respectively. The results showed that Fe 3 O 4 at MCM-41/CPS was the best nanomaterial for PPL immobilization, exhibiting enhanced immobilization efficiency (maximum 96%), maximum relative activity (up to 96%), high stability and reusability (83% 56 days and 86.7% ten cycles). Additionally, it offered some other advantages, such as easy recycling and reuse, complying with the trend of green chemistry. Therefore, Fe 3 O 4 at MCM-41/CPS in combination with a relevant method can be proposed for commercial applications.
危险品化学品经营许可证(带存储)