Thin Films Containing Silver Nanoparticles: Their Preparation And Physical Properties

Nanocomposite adding nanoparticles to coatings have attracted widespreadattention in the scientific community. Nobel metallic nanotechnology can be introducedto biomedical which can be guided by physics methods and the technique of materialspreparation to develop antimicrobial coating applied to biomedical to meet the needs ofthe biomedical field. Based on the above background, the impact of graphene oxide tocoating property containing silver was investigated in this thesis.First of all, Ag-PhTEOS films with graphene oxide were prepared by the sol-gelmethod. The effect of molar ratio of Ag/Si in the precursors solution on the size of silverparticles and the absorption spectrum was studied. It was found that with increasing ofmolar ratio of Ag/Si, silver particles on the surface of the film will be increased and thesize will be enlarged. And the intensity of the absorption spectrum will be increased.Also there is a redshift in the peak position of silver in the absorption spectrum. In orderto keep the nanoparticles remaining100nm, there is an upper limit of molar ratio ofAg/Si which is21.4%. When continue to increase the molar ratio of Ag/Si, silverparticles will lose the nanoparticles, and this problem can be resolved by heating thefilm at200C. Secondly, The effect of temperature on the structure and properties ofcoatings containing silver was studied. It was found that the film dried in100Cin theair for1h, most silver particles gather on the surface of the coating. As the temperaturerises to200C, more silver particles embedded into the interior of coating and the silvercontent on the surface reduces. Also the concentration of silver ion in deionized waterreduced significantly and there is a blueshift in the peak position of silver in theabsorption spectrum.Furthermore, the effect of graphene oxide on the size of silver nanoparticles on thesurface of the films, content of silver, optical properties and silver release of films in thedeionized water were studied. By comparing the AFM images of the film with GO andwithout GO, it was found that silver nanoparticles on the surface of the film with GOare more dense, more uniform. By comparing their optical absorption properties, it wasfound that GO make more silver attached to the coating. By comparing theconcentration of silver ion of the two films in deionized water, it was found thatgraphene oxide-containing film can release more silver ions at the same time, and thiswill lead to more effective antibacterial effectiveness. It can be concluded that grapheneoxide can induce more silver ions into silver particles in thin film effectively.The results of the thesis will promote people to understand the direction ofpreparation and properties of silver-containing coating effectively and to promote the practical application of antibacterial coating in the biomedical field.