Nanocellulose-silica polyethersulfone hybrid composite stabilized lipase for esterification

Abstract

An alternative environmentally benign support was prepared from nanocrystalline silica (SiO2), and cellulose (NCC) acquired from oil palm fronds leaves (OPFL) for incorporation with polyethersulfone (PES). The resultant PES-SiO2-NCC support was then used for covalent immobilization of Candida rugosa lipase (CRL/PES-SiO2-NCC). FTIR-ATR spectral data of SiO2-NCC indicated that NCC was hydrogen-bonded to SiO2 based on the characteristic wavenumbers at 1735 cm-1 and 1650 cm-1 for NCC, 1732 cm-1 and 1657 cm-1 for SiO2, alongside decreased peak intensity and the overall downshifted wavenumbers, respectively. X-ray diffractograms of NCC and SiO2 showed crystallinity indices of 68% and 70%, respectively, implying their crystalline nature. The CRL/ PES-SiO2-NCC biocatalyst yielded pentyl valerate as high as 78.3% after 2 h using a 0.02 cm membrane size and 5% (w/v) incorporation of SiO2-NCC but in the absence of the pore former, PVP K30. The findings invariably envisage the biocompatibility of NCC and SiO2 derived from OPFL as a hybrid nano-filler to prepare the PES-SiO2-NCC composite for lipase immobilization.