Preparation, Characterization, and Antimicrobial Activities of ZnO Nanoparticles/Cellulose Nanocrystal Nanocomposites

Abstract

Zinc oxide (ZnO) nanoparticles were synthesized within cellulose nanocrystals (CNC) as a new stabilizer by a precipitation method for antimicrobial applications. For fabrication of ZnO/CNC nanocomposites, solutions with different molar ratios of Zn to CNC were prepared in ethanol as the solvent. ZnO/CNC was separated from the suspension and then dried at 120 °C for 1 hour. The nanocomposites were characterized using Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis), X-ray diffraction (XRD), transmission electron microscope (TEM), and thermogravimetric (TG) analyses. According to the XRD and TEM results, the ZnO nanoparticles with a hexagonal wurtzite structure were easily prepared and dispersed in the CNC with an average size of less than 20 nm. The average size of the ZnO nanoparticles increased with increasing molar ratio of ZnO to CNC. The best ratio of Zn:CNC was chosen based on the small size of the ZnO nanoparticles that yielded better antimicrobial and thermal properties. The UV-vis absorption spectra of the ZnO/CNC nanocomposites showed absorption peaks in the UV region that were ascribed to the band gap of the ZnO nanoparticles. The antibacterial effects of ZnO/CNC were stronger compared to ZnO nanoparticles.

Green synthesis palladium nanoparticles mediated by white tea (<em>Camellia sinensis</em>) extract with antioxidant, antibacterial, and antiproliferative activities toward the human leukemia (MOLT-4) cell line

“…E. coli, a Gram-negative bacterium, possesses an external lipopolysaccharide membrane that protects the peptidoglycan layer and allows the bacteria to survive in harsh environments. 33 Presumably, this protective layer is one of the contributing factors toward the greater ability of E. coli than S. epidermidis to survive the toxic effects of white tea extract and Pd@W.tea NPs.…”

Mechanical and Structural Characterization of Eco-Friendly Films Prepared Using Poly(vinyl alcohol), Cellulose Nanocrystals and Chitosan Nanoparticle Blend

“…Prajakta et al [23] discussed that zeta potential around 30 mV produces homogenous and stable nanoparticles. It can be observed from Table-2 that mechanical properties changed with varying concentration of nanomatreials and the polymer PVA; in case CNC, with increse in concentration both the tensile sterngth and elongation, similarly in case of incorporation of nanoparticle, this can be correlated with the finding reported by Azizi et al [24]. The formation of hydrogen bonds formed between CNC and PVA matrix, which restricts motions and promotes rigidity.…”

Preparation and properties of poly(vinyl alcohol)/chitosan blend bionanocomposites reinforced with cellulose nanocrystals/ZnO-Ag multifunctional nanosized filler

“…The difference in antibacterial activity of the bionanocomposites against these two types of bacteria can be related to structural and chemical compositional differences in the cell membrane. 41 …”