Synthesis of silver nanoparticles using dialdehyde cellulose nanocrystal as a multi-functional agent and application to antibacterial paper

Development of a reliable and rapid process for synthesis of stable silver nanoparticles using nanocellulose is highly desired. In the present study, we report an efficient approach for the synthesis of stable silver nanoparticles (AgNPs) using dialdehyde cellulose nanocrystal (DACNC) as both reducing and stabilizing agent. The periodated cellulose nanocrystals (CNCs) were able to reduce silver ions to obtain cellulose nanocrystal-AgNPs (CNC-AgNPs) composites with high Ag percentage. The resulting composites were characterized by using UV-Vis spectroscopy, fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Furthermore, their antimicrobial activities were investigated. The formation of AgNPs was evidenced by the surface plasmon resonance peak at around 400nm. XRD data showed diffraction peaks at 2 38.33o, 44.55o, 64.27o, 77.66o, which can be indexed to (111), (200), (220), (311), and (222) planes of pure silver, indicating the successful synthesis of silver nanoparticles. The TEM images of CNC-AgNPs showed spherical AgNPs with sizes from several nanometers to 30nm on the cellulose nanocrystal surfaces. The composites showed high antibacterial activities against Escherichia coli and Staphylococcus aureus. When the CNC-AgNPs was added into the pulp fibers, the obtained handsheets also displayed strong antibacterial activities with higher strength properties and a lower air permeability, indicating potential applications in food packaging materials. [GRAPHICS] .