载银sod基纳米分子筛的合成及抗菌性能

Synthesis and antibacterial properties of silver⁃loaded sod⁃based zeolite

采用两步法合成了sod基系列分子筛(EMT、FAU、SOD),并通过离子交换法引入Ag^(+)得到载银分子筛,通过X射线衍射(XRD)、扫描电子显微镜(SEM)证明离子交换前后分子筛骨架结构和晶粒尺寸没有发生明显变化;通过红外光谱(IR)、热重(TG)证明制得的载银分子筛具有良好的稳定性;对获得的载银分子筛进行了Ag^(+)释放实验与抗菌能力测试,考察了分子筛种类和晶粒尺寸对抗菌性能的影响。结果表明具有笼状结构的FAU与EMT分子筛因可储存更多的Ag^(+)而具有更好的抗菌性能,而具有超笼结构的FAU分子筛抗菌性能最优。通过对比不同晶粒尺寸载银FAU分子筛抗菌数据发现,晶粒尺寸为100 nm的载银FAU分子筛因外表面丰富的抗菌活性位点以及其内部可以储存并不断释放Ag^(+)而具有最优的抗菌性能和抗菌寿命。而晶粒尺寸为10 nm的载银FAU分子筛由于晶粒尺寸较小、外比表面积大、扩散路径短,Ag^(+)的释放速率最快,抗菌效率最高。

A series of sod-based zeolites(EMT,FAU,SOD)were synthesized by two-step method,and Ag^(+)was introduced by ion exchange method to obtain silver-loaded zeolite.X-ray diffraction(XRD)and scanning electron microscope(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 antibacterial 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 zeolite were summarized.