Self-Assembly of Hierarchically Structured Cellulose@ZnO Composite in Solid–Liquid Homogeneous Phase: Synthesis, DFT Calculations, and Enhanced Antibacterial Activities

Abstract

To explore the interactions of nanoparticles and bioresources and elucidate their effects on the morphology of the resulting composite, hierarchically structured cellulose@ZnO composites have been synthesized by an environmentally friendly hydrothermal method in one step. First, self-assembly induces the formation of hierarchical three-level structures, including cellulose/ZnO nanofibers, layers, and microfibers. Then, ZnO microparticles deposit onto the surface of the third-level cellulose/ZnO microfibers and accomplish the fabrication of a cellulose@ZnO composite, which eventually defines the hierarchical morphology of synthesized materials. The self-assembly mechanism was comprehensively examined. The electrostatic attraction between cellulose and ZnO, not hydrogen bonding, was found to be the main driving force for the formation of the first-level structure. A density functional theory study was conducted to support the self-assembly mechanism by optimizing the cellulose/ZnO structures at the molecular level, computing the corresponding thermodynamic energies and examining the spectroscopic properties. A hierarchically structured cellulose@ZnO composite is found to enhance the antibacterial activities. The diameters of the inhibition zone were found to be 48.8 and 45.5 mm against the Gram-positive bacterium Staphylococcus aureus (S. aureus) and the Gram-negative bacterium Escherichia coli (E. coli), respectively. This study is expected to improve food packaging materials while utilizing our newly synthesized cellulose@ZnO composite.

Cellulose Nanomaterials in Biomedical, Food, and Nutraceutical Applications: A Review

“…A hierarchically structured cellulose@ZnO composite was found the enhanced antibacterial activities with diameters of the inhibition zone were found to be 48.8 and 45.5 mm against the S. aureus and the E. coli , respectively. It is indicated that the cellulose@ZnO composite material can be utilized to improve food packaging materials . CuO nanoparticles impregnated bacterial cellulose and chitosan nanofibers were fabricated to enhance the antibacterial activity for food packing applications.…”

Preparation of ternary ZnO/Ag/cellulose and its enhanced photocatalytic degradation property on phenol and benzene in VOCs

“…In low pH conditions, small ZnO particles are found on the surface of cellulose (Figure 2a-c); increase the pH to 12, ZnO microparticles about 300 nm length and 50 nm width are observed (Figure 2d). According to a previous study, ZnO nanoparticles with certain sizes are easily to selfassemble with cellulose [30]. However, in this study, we didn't find the same size ZnO nanoparticles on prepared cellulose composite.…”

“…Cellulose@ZnO composite was prepared by the hydrothermal method used in previous research [30]. 3.0 g zinc acetate and 1.0 g cellulose were dissolved in 25 mL distilled water.…”

“…In this work, we used ultrasonic-assisted hydrothermal method to synthesize the ZnO/Ag/cellulose (ZAC) composite. The results indicate that the ZAC possesses the enhanced photocatalytic activity compared with ZnO/ cellulose [30]. The photocatalytic property of degrading benzene, phenol and their derivatives were fully studied.…”

Nanocomposites: suitable alternatives as antimicrobial agents

“…The antimicrobial efficacy of this nanocomposite has shown to be dependent on the concentration of zinc oxide nanoparticles in the composition. Studies have demonstrated that as the amount of zinc oxide increases, the antibacterial activity also increases (Yu et al, 2014;Zhao et al, 2017). Quantitative analysis of the minimum inhibitory concentration (MIC) of zinc oxide-cellulose nanocomposites revealed that the MIC for S. aureus is 0.44 mg/mL -1 , whilst for E. coli it is 0.63 mg/mL -1 (Zhao et al, 2017).…”