新型巯基功能化二氧化硅微球的制备及其对银离子的吸附

Facile preparation of thiol-functionalized SiO_2 microspheres and their adsorption to silver ions

表面具有大量巯基的二氧化硅微球与介孔二氧化硅一样,具有吸附重金属离子的功能。通过溶胶凝胶一步法制备巯基功能化的二氧化硅微球,该微球粒度分布均匀、成球率高,直径在1μm左右。红外和拉曼光谱证明,微球表面富含大量的巯基,超短的吸附平衡时间说明巯基与Ag+迅速螯合,而不同于介孔的扩散吸附。溶液的p H对Ag^+吸附量的影响不明显,巯基功能化的微球对Ag^+的吸附遵守Slips等温模型,最大吸附量能够达到102 mg/g,并且拟合度达到99.6%。

The SiO2 microspheres with abundant thiol on the surface have the same property of adsorption to heavy metal ions as that of the mesoporous silica.In one-pot,the thiol-functionalized SiO2 micro-spheres were prepared by a sol-gel method,and SiO2 microspheres had a narrow particle size distribution and well sphere with diameter around 1 μm.FTIR and Raman spectroscopy confirmed there were a great amount of thiols on the surface of microspheres.Meanwhile,the adsorption process of silver ions by the microspheres finished within u1 tra-short time,which was in accord with the chelation of silver ions and thiols.And that was different from the diffusion adsorption of mesoporous silica.Furthermore,the pH value of solution had little effect on the adsorption capacity of silver ions and the adsorption maximum is 102 mg/g in Slips isotherm with R^2 =99.6%.