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An antibacterial cellulose oligomer was synthesized by cellodextrin phosphorylase (CDP) from glucose 1-phosphate (G1P) using a glucoside with an antibacterial group as a primer, then a hydrophilic cellulose molecular coating with excellent anti-fouling and anti-bacterial properties on PVDF membrane surface was carried out by dissolving the synthetic cellulose into a homogeneous solution. [Display omitted] • The antibacterial cellulose was synthesized from G1P in one step catalyzed by CDP. • Hydrophilic coating fabricated in one step showed high water flux. • Cellulose coating showed excellent anti-fouling and anti-bacterial performances. Synthetic cellulose prepared by enzyme has the advantages of easy functionalization, easy preparation, and biocompatibility, making it an ideal material for constructing hydrophilic coating with functionalities. In this study, β-D glucose with phenolic group (arbutin) as a primer reacted with glucose 1-phosphate (G1P) under the catalysis of Clostridium thermocellum (CtCDP) to synthesize antibacterial cellooligomer. Then, the synthetic cellooligomer was dissolved into a homogeneous organic solution to prepare a functional hydrophilic coating composed of cellulose molecular chains on the surface of polyvinylidene fluoride (PVDF) membranes. The molecular structure of enzymatic antibacterial cellooligomer was characterized by fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance spectroscopy (1H NMR). ATR-FTIR confirmed the successful preparation of cellulose coatings. The performance test results showed that the strong interaction at the interface between cellooligomer and PVDF membrane promoted the uniform distribution of cellulose molecules on the membrane surface, which greatly improved the hydrophilicity of PVDF membrane and enhanced the stability of the coating bonded to the substrate. Moreover, the cellulose molecular coating had excellent antifouling performance, outstanding antibacterial activity, and anti-adhesion to Staphylococcus aureus (S. aureus). This work provides a versatile platform for the time-saving and cost-effective fabrication of antifouling and antibacterial membranes. [ABSTRACT FROM AUTHOR]

Hydrophilic PVDF membrane was fabricated in single step via cellulose molecular coating prepared by homogeneous solution of cellulose oligomer synthesized by enzyme catalysis (EC)/Trifluoroacetic acid (TFA). Both smooth and rough coatings can be prepared by regulating the aggregative structure of cellulose molecular coatings. The chemical structures of the cellulose and its coating were confirmed by 1H Nuclear Magnetic Resonance Spectroscopy (1H NMR) and Fourier Transform Infrared Spectroscopy (FTIR). The aggregation structure of the cellulose coating was characterized by wide-angle X-ray diffraction (WAXD). X-ray Photoelectron Spectroscopy (XPS) studies unveiled the strong binding of cellulose molecular to PVDF membranes at the interface. Scanning Electron Microscopy (SEM) morphologies show that the cellulose molecules were uniformly coated on the surface and cross section of the membranes. Water contact angle measurement suggested that cellulose molecular coating possessed high hydrophilicity and wetting rate, giving the PVDF membranes high water flux and excellent anti-fouling performances. The coated membranes also show excellent adsorption and desorption performances for crystal violet (CV). The superior performances of incompletely crystallized cellulose coating over amorphous cellulose coating were attributed to the increased specific surface area resulting from the surface roughness. The construction of cellulose molecular coating with controlled aggregation structure provides a novel efficient technology in the field of purification of wastewater, opening up a new approach to the microstructural manipulation of the hydrophilic coating. A novel strategy to prepare the cellulose molecular coating with versatile functions. [Display omitted] • Hydrophilic PVDF membrane was fabricated in one step via cellulose molecular coating. • The surface roughness of coating can be regulated based on the aggregation state. • Cellulose coating showed high water flux and excellent anti-fouling performances. [ABSTRACT FROM AUTHOR]