通过柠檬酸改性提高载银活性炭的抗菌性能

Improvement of Antibacterial Activity of Activated Carbon Supported Silver Modified with Citric Acid

通过负载柠檬酸对活性炭进行改性,用N2吸附法测定活性炭的比表面积,用AAS、SEM、XRD测试技术分析了银在活性炭上的吸附和分布,并研究了载银活性炭的抗菌性能。结果表明,负载柠檬酸使活性炭的比表面积下降约24%,但载银后活性炭的比表面积增大。柠檬酸改性为[Ag(NH3)2]+的还原吸附提供更多的活性点,使银的吸附速率加快,吸附量提高约25%,表面的银颗粒变得非常密集,粒径减小,且颗粒均匀,因此抗菌性能显著增强,其中对金黄色葡萄球菌的杀灭效果明显优于对大肠杆菌的,同时对于高分散Ag/C催化剂的制备及银的回收也具有重要的价值。

Specific surface area of activated carbon（ AC ） treated with citric acid solution was determined by Niadsorption technique, and the adsorption and distribution of silver on the AC were investigated by AAS, SEM, XRD. The antibacterial activities of the AC supported silver（AC/Ag） against Staphylococcus aureus （S.aureus） and Escherichia coli（E, coli） were investigated. The results show that the citric acid modification reduced the number of cracks and cavities on the activated carbon, reducing the specific surface area of AC by about 24%, but the surface area increased after silver was leaded. The citric acid modification created more surface groups that improved the adsorption of silver ion by 25 %. Silver granules became denser and smaller and more uniform after the modification. This modified AC/Ag catalyst possesses a stronger antibacterial activity for the growing of E. coli and S. aureus than the unmodified AC/Ag catalyst, and it has a stronger inhibitory effect on the growing of S. aureus than E. coli. Additionally, the citric acid modification is advanta- geous to the preparation of effective AC/Ag catalysts and the extraction of silver from solutions.