Preparation of mesoporous nanofilm constructed millimeter-sized macroporous SiO2 for lipase immobilization

• DOI: 10.1016/j.micromeso.2021.111227
• Publication Date: 2021-06-07T17:11:54Z
• Authors: Fang Zhao; Hui Zhang; Ziyi Zhang; Yunxiao Liang
• Keywords: Macropore

Abstract A novel mesoporous nanofilm constructed millimeter-sized macroporous SiO2 (MNCMMS) was prepared through a dual-templating method, using an epoxy resin macroporous polymer with three-dimensional skeleton structure as the shape and macropore structure directing agent and polyethylene glycol 20000 (PEG20000) as the mesopore porogen. MNCMMS was used as the support for immobilization of Pseudomonas fluorescens lipase (PFL) in order to overcome the limitations of the immobilized enzyme on mesoporous nanomaterials and to improve the performance of PFL. The immobilization conditions and the properties of the immobilized PFL were investigated. The structures and properties of the as-prepared materials were investigated by various characterization techniques. The results revealed that MNCMMS possessed two sets of three-dimensional continuous pass-through macroporous channels with uniform pore size (700 nm), large specific surface area (317 m2/g) and pore volume (89.2%), high mechanical strength (10.4 MPa), and that the macropore wall was a continuous mesoporous (pore size of 10 nm) nanofilm with the thickness ranging from 40 to 50 nm. Under the optimum conditions, the activity of PFL@MNCMMS reached to 4897 U/g and enzyme activity recovery achieved to 255%. Compared with free lipase, the stability and reusability of the immobilized lipase were significantly improved. Moreover, the immobilized lipase can be easily recovered from the reaction system for reuse.