Preparation And Properties Of Ag-loaded Al-based Porous Materials

Nano Ag has many advantages,such as high efficiency,wide range and long lasting antibacterial activity,is widely used in industry,environmental protection,medicine and other fields,but its antibacterial properties are reduced by the agglomeration of the dimensional effect which limits the application of Ag in the field of antibacterial.In order to solve the problem of agglomeration in the process of preparation and use of the nano-Ag/Al2O3 materials,improving the O adsorption and antibacterial properties.In this paper,the method of investment casting and impregnation was used to prepare the Ag supported Al based porous material.The preparation,O adsorption and antibacterial properties of nano-Ag supported Al based porous materials were studied,the main results are as follows:(1)The porous aluminum based support with porous structure of 25PPI and 30PPI was prepared by the method of investment casting using pure aluminum.Through the experiment,we found that the pore structure of porous aluminum based material is closely related to the liquid aluminum temperature,mold temperature and pressure parameters,when the zero defect plaster mold is used as precursor.And the optimum process parameters of the preparation of the porous aluminum based material are as follows:the temperature of aluminum liquid is 760～780 C,the mold temperature is 530℃,the pressure is 0.35MPa.(2)Nano-Ag was supported on porous aluminum by the method of impregnation.Through the analysis about the morphology of Ag which supported on the surface of porous aluminum,we found that the spherical particle shape of nano-Ag with the size of 100～200nm was prepared as follows:firstly,impregnating in the silver ammonia complex 1h which made up the concentration of AgNO3 was 1%,and then drying and reducng in Ar90%+ H290%at 250℃ with 3h.And nano-Ag dispersed evenly and no agglomeration occurred under this parameter condition.(3)The surface elements of the sample were analyzed by XPS.The analysis results show that the interaction will happen between AI and Ag during the process of sintering,and form Al95Ag5.The amount of Al95Ag5 in oxidized sample is more than that in reduced sample,but the increase of A195Ag5 is unfavorable to the interaction between Ag and O.Compared to the reduced samples,the oxidized samples can adsorb more O,the binding energy is higher,the analysts believe that the O in the oxidation state samples is O atoms in deeper layer or absorption O of surface molecules,and the O in the reduced samples is atomic adsorption O.(4)The bactericidal effect of reduced and oxidized Ag supported Al based porous material on escherichia coli and staphylococcus aureus was discussed.The results show that sterilization rate of the reduced samples was significantly better than that of oxidized samples,the sterilization rate of reduced samples can reach 95%,the sterilization of staphylococcus aureus rate can reach 98.6%within 60min,which shows good sterilization effect.In addition,the antibacterial properties of Ag do not increase with the increase of O adsorption capacity,but are closely related to the form of Ag and O.