Research On Synthesis And Functions Of Protein Conjugated Zinc Oxide Nano-Composites And 2-D Thin Films

Zinc oxide nano-materials(ZnO)have wide applications in many fields because of its small particle size,large specific surface area,more active sites,especially in photocatalytic and antibacterial fields.In this thesis,biomimetic synthesis technology was applied to synthesize corn protein conjugated zinc oxide nanocomposites under facile conditions by using zein as template,which is cheap and easy to get.The morphology was observed by High-resolution transmission electron microscopy and Scanning electron microscope.The composites and content of the nano-materials were analyzed by XRD,FTIR,and TG-DSC.Taking into account lacks of nano-materials at the recovery and recycling uses,we further improved protein conjugated zinc oxide nano-composites by endowing magnetic properties to it or fabricating it into 2-D thin films.Finally,the photocatalytic activity and biological activities were also assessed respectively.This thesis contains the following three parts:(1)The nano-composites with well uniform and dispersity were synthesized.The antibacterial results by disk diffusion method showed that the synthetic nano-composites could significantly inhibite the growth of Escherichia coli and Staphylococcus aureus and the inhibitory effects exhibited a dosage-dependent mode.At the same time the photocatalytic results showed that Zein-ZnO had a good activity and stability at the degradation of on methyl orange under the illumination of 600 w high pressure mercury lamp.(2)The ion dsorption method was developed to synthesize magnetic protein conjugated zinc oxide nano-composites under facile conditions.The antibacterial results by disk diffusion method showed that magnetic nano-composites still had significantly antimicrobial activity against Escherichia coli and Staphylococcus aureus and the inhibitory effects exhibited a dosage-dependent mode.The degradation of magnetic Zein-ZnO on methyl orange got to 56.84% in 15 min and 68.77% in 120 min,respectively.However,the photocatalytic stability of the nano-composites need to be futher explored.(3)The transparent and uniform Zein-ZnO film was fabricated by solution evaporation method.The thin films were stable in aqueous solution with different pH values.And the highest release got to 17.4% after four week at pH=7.The antibacterial results showed that Zein-ZnO films could significantly inhibite the growth of Escherichia coli and Staphylococcus aureus.Furthermore,the thin films after 4 weeks of immersion in aqueous solution still kept high antibacterial activity.The photocatalytic results showed that the degradation of thin films on methyl orange achieved 6.32% in 15 min and 24.56% in 120 min,respectively.The thin films had a bad activity at the degradation of on methyl orange.