Synthesis and Characterization of Ag/Chitosan Nanobiocomposite by Chemical Method and Investigation of its Application for Food Packaging

Chitosan is a biodegradable and antibacterial polymer with simple preparation methods. The main problem of its film is its poor mechanical stability and amphiphilic structure. In this research Ag nanoparticles was synthesized in the matrix of chitosan (biopolymer) to reduce humidity absorbance and increase mechanical stability for application in food packaging. AgNO3 and Na2H2B4 and chitosan was used as precursors. The characteristic of nanoparticles and film was studied by X-Ray diffraction pattern. Surface morphology of the film was studied using scaning electrone microscopy. The result of the X-ray diffraction analysis showed that the maximum absorbance of the silver nanoparticles belongs to (111), (200), (311) and (222) direction and the domain phase of silver crystals are cubic. Scanning electron microscopy image revealed homogenous distribution of nanoparticles in polymer film. The microbial results showed an antibacterial effect for Ag nanoparticles in chitosan solution against gram negative bacteria. Furthermore, it didn’t show any effect against gram positive bacteria. Antibacterial activity of the composite was studied by the inhibition zone effect against Gram positive and gram negative using Muller-Hinton agar in different concentration of AgNO3. The result demonstrated that the maximum antibacterial activity was observed in the concentration of 0.15 mol/L. The effect of nanoparticles in the humidity absorbance of the film was investigated. WVP was decreased from 7.6% to 5.7% g/m.h.Pa.