Synthesis and antibacterial properties of silver-loaded sod-based zeolite
A series of sod-based zeolites(EMT,FAU,SOD)were synthesized by two-step method,and Ag+was intro-duced by ion exchange method to obtain silver-loaded zeolite.X-ray diffraction(XRD)and scanning electron micro-scope(SEM)showed that the structure and grain size of the zeolite did not change significantly before and after ion exchange.It was proved by infrared(IR)and thermogravimetry(TG)that the silver bearing zeolite had good stability.The Ag+release experiment and antibacterial activity test were carried out on the prepared silver-loaded zeolite,and the effects of zeolite type and grain size on antibacterial performance were investigated.The results showed that the cage structure of FAU and EMT zeolite had better antibacterial properties because they could store more Ag+,and the super cage structure of FAU zeolite had the best antibacterial properties.By comparing the antibacterial data of FAU zeolite with different grain sizes,it was found that the FAU zeolite with grain size of 100 nm had the best anti-bacterial performance and antibacterial life because of the abundant antibacterial active sites on the outer surface and the Ag+could be stored and released continuously inside.The silver-loaded FAU zeolite with grain size of 10 nm had the fastest Ag+release rate and the highest antibacterial efficiency due to its small grain size,large external specific surface area and short diffusion path.The factors affecting the antibacterial properties of silver-loaded zeo-lite were summarized.