反应温度对蒙脱石载银量及其缓释性能的影响

以钠基蒙脱石(Na-MMT)为载体,氧化银与氨水反应形成的银氨络合物Ag(NH₃)₂OH]为前驱体,通过离子交换和三乙醇胺(TEA)还原两步法制备了载银蒙脱石(Ag-MMT)。 用佛尔哈德法测定了载银蒙脱石(Ag-MMT)的载银量,探讨了反应温度对MMT 载银量及其缓释性能的影响,并用FI-IR、XRD等技术手段对Na-MMT和Ag-MMT的结构进行了表征。 结果表明,在蒙脱石与Ag⁺的质量比为20:1、离子交换时间为1 h、反应温度50 ℃,然后再加入三乙醇胺和聚乙烯吡咯烷酮,50 ℃下反应2 h,MMT的载银量最大,银的利用率达到86.89%,释放时间最持久,并且MMT的层状结构没有被破坏。

Influence of Reaction Temperature on the Amount of Silver Loaded on Montmorillonite and Its Sustained Release Performance

Silver loaded montmorillonite(Ag-MMT) was prepared by ion-exchange and triethanolamine reduction two-step approach using Ag(NH₃)₂OH] as the precursor for silver oxide and ammonia. The silver content in Ag-MMT was determined by the Volhard method. The effects of reaction temperature on silver loading, its release properties, and the structures of Na-MMT and Ag-MMT were characterized by FI-IR and XRD, respectively. The results show that the amount of silver loaded on the montmorillonite is maximum, the utilization rate of silver reaches up to 86.9% and the layered structure of MMT is remained under the optimized conditions:the mass ratio of montmorillonite to Ag⁺ is 20:1, the ion exchange time is 1 h, and the reaction temperature is 50 ℃, then triethanolamine and polyvinylpyrrolidone are added and react for 2 h at temperature of 50 ℃.