The Bi-functionalized Of Mesoporous Material And Its Study On The Absorption Of Heavy Metal Ions

Mesoporous materials have been a hot research topic because of their adjustable pore diameters, relatively large specific surface areas and the pore volumes. There are lots of researches in domestic and overseas on the heavy metal ions absorption with one functionalization group, while there are few researches done on the heavy metal ions absorption with bi-functionlized mesoporous materials. In this thesis, the mesoporous materials are first modified and then used to absorb the heavy metal ions.The conditions of the hydrolysis reaction of the two silane coupling agents (APTES and MPTMS) are discussed first. Then the effect of different static durations and the reaction temperatures on the content of the-SH functionalized group in the mesoporous materials are considered and the best conditions are achieved. As the experiment data show the content of the-SH functionalized group of3-hour static duration is almost the same when the time is extended. After3-hour static duration and automatic filtration, the material synthesized is dried at the temperature at120Centigrade for4consecutive hours. The functional materials made this way manifest the biggest content of-SH functionalized group.Three kinds of bi-functionalized materials, MCM-41-NH-SH, MCM-41-SH-NH and MCM-41-SH(-NH) are synthesized in the best condition. Later the three bi-functionalized materials are applied to absorb the heavy metal ions in the single metal ions[Cu(Ⅱ), Zn(Ⅱ), Cr(Ⅲ), Pb(Ⅱ)] solutions at the concentration of0.5mmol/L and the mixed heavy metal ions[Cu(Ⅱ), Zn(Ⅱ), Cr(Ⅲ), Pb(Ⅱ)] solutions at the concentration of0.5mmol/L at2different pHs (pH=4and pH=5), the data about the heavy metal ions absorbed by the three kinds of bi-functionalized materials are gathered in this experiments. And the absorptions of the Cr(Ⅲ) by the three bi-functionalized materials at pH=4are investigated to study the kinetics of the absorption of the heavy metal ions by the mesoporous materials.As shown in the data, the bi-functionlized materials have low absorption of the heavy metal ions in the single heavy metal ion solutions and the mixed heavy metal ions solutions at pH=5, while the materials have relatively high absorption of the Pb(Ⅱ) and Cr(Ⅲ) in the heavy metal ions solution at pH=4, the absorption abilities are46.85mg/g and56.92mg/g respectively. The results show that the adsorption of the heavy metal ions by the bi-functionlized mesoporous materials is more likely to be the second-order kinetic model than the first-order kinetic model. Finally, outlooks of mesoporous modifications and the bi-functionalized materials in the absorption of the heavy metal ions solutions are offered.