Nanocellulose-silica polyethersulfone hybrid composite stabilized lipase for esterification

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.