Study On The Preparation And Characteristics Of Nano-Zinc Oxide Antibacterial Materials

The control and elimination of harmful bacteria around the living space, which is significant to our health, becomes a hot topic with the demands of improving our living standards. The inorganic antibacterial materials became a hotspot in this field because it has a lot of merits and a promising market. Nano-ZnO can overcome the disadvantages of silver and TiO2 antimicrobial, such as changing color and needing ultraviolet radiation, etc. The ZnO particles in nanometer scale has a good performance in antibacterial aspect, so it is one of the focuses now.This paper studied the preparation process of nano-ZnO, and the nanoparticle has been characterized through UV-Vis spectra, XRD and TEM. The nano-ZnO's antibacterial performance is also tested and the nanoparticle has been applied to polymer films to make them have the antibacterial function. The effect of preparation process to the performance of ZnO antibacterial materials is discussed in this paper either.This paper used sol-gel method to prepare nano-ZnO particles, and found that the molar ratio and concentration of reactants, the time and temperature of the reaction and the temp. of desiccation all have effect on the formation of particles. We fixed a optimized route of preparation process: reactant ratio [Zn(Ac)2]:[NaOH]=1:2, reaction time=30min, reaction temp.=0℃,the concentration of Zn2+ =0.05M, temp. of desiccation=60℃,time of . desiccation=24h.UV-Vis spectra indicated that: with the increase of reaction time, reaction temp. and the concentration of Zn2+, the diameter of ZnO particles increased,the stability of nano- ZnO colloid decrease with the increase in the diameter of nano-ZnO particles.The results of XRD shows that: the purity of products is low and the major impurity is Zn(OH)2 when the molar ratio of reactants is 1:1.5; but it has a satisfied purity when it changed to 1:2. This trend is accord with the analysis of UV-Vis spectra. The TEM photos indicated the change of the diameter of nanoparticles is agreed with the change of the concentration of Zn2+ . The shape of nano-ZnO particles changed from sphere to pillar with the increase of the concentration of Zn2+.The test of antibacterial property showed that the MIC of nano-ZnO has a range of 125PPM to 500PPM. The minimum of MIC value is 125PPM regardless of changes in process. And it also indicated that the MIC value is increase when the diameter of particles increase, but the diameter should be larger than 13nm.The performance of the ZnO antibacterial thin film is excellent, its Sterilizing efficiency can be 100%. Both the photocatalysis mechanism and the dissolving of metal ion mechanism can be the reason of the antibacterial performance.