Research Of AgNPs And Its Composite Antibacterial Material

Nano silver are silver nanoparticles, mainly between1nm and100nm in size,which can be prepared by chemical or physical methods. Because of its quantμm sizeeffect, small-size effect, surface effect and macroscopic quantμm tunneling effect, thenano silver has been one of the most promising materials in twenty-first century. Thenano silver has a wide application prospect in magnetic materials, electronic materials,optical materials and high strength, high density material sintering, catalysis, sensing,etc. Various nano silver composite materials with anti-bacterial property can beprepared by adding silver Nanoparticles. Silver ion is of most concern in metal ion usedas.antibacterial agentIn this study, spherical, rodlike and linear silver nanoparticles with differentdiameters were prepared by the combination of microwave heating and chemicalcatalysis. The results showed that PVP is beneficial to the dispersion of nanoparticles byimproving the electrostatic repulsion between the nano silver powders. The higherreaction temperature is beneficial to the reaction, which accelerated nucleation rate ofthe silver particle and thus reduced the particle size. Increasing the concentration of thereactants would result the increased growth and agglomeration of the particles. By theintroducing Cl-and properly controlling the reaction time, the products could transformfrom spherical to rodlike nanoparticles.Rodlike silver nanoparticles with the diameter of30~50nm and the length of50nmwere synthesized by microwave heating method. By transmission electron microscopy(TEM), UV-Vis spectra, and XRD analysis, EDX and other methods, we observed themorphology of the nano particles and studied the relationship between structure andformation mechanism. The formation of Rodlike silver nanoparticles can be dividedinto three stages. Stage Ⅰ, spherical silver with small size were generated in thepresence of Cl-. StageⅡ, with the PVP as templates, a large nμmber of triangular silvernanoparticles were generated with a small amount of rod-like structure of silvernanoparticles. Stage Ⅲ, the triangle particles combined to form rod-like structure silver nanoparticles, which kept constantly transforming and binding, and finally grew into arodlike structure.To evaluate the antibacterial Performance of the nano silvers, we fabricatedAg/GA/PVA composite materials by electrospinning technique. By adjusting theelectrospinning parameters, we successfully prepared nanofibrous antibacterialmaterials with high tensile strength, excellent elasticity and good water absorption.Using SEM, XR, UV-vis and other testing methods, we confirmed the goodantibacterial property of Ag/GA/PVA composite materials through antibacterial test andcytotoxicity test.In this thesis, we produced composite material with core-shell structure, whichexhibited excellent antibacterial in long term confirmed by the SEM characterizationand antimicrobial test. Furthermore, the electrical properties and optical properties ofnano silvers were investigated. Silver paste with excellent conductive performance wasalso prepared, and the surface Raman scattering activity.was tested.