Preparation And Characterization Of Amino Modified SBA-15 And Its Adsorption Properties For Pb ^{2 +}

Mesoporous material SBA-15 has been favored by many researchers because of its large specific surface area and pore size. But the lack of active center in the framework of pure silicon SBA-15, the ability to adsorb heavy metal ions is poor.Therefore, more and more researchers to modify the pure silicon SBA-15 for research.The modified mesoporous materials amino（NH₂-SBA-15）, diamine（2N-SBA-15）, triamino（3N-SBA-15） were prepared by one pot synthesis method and a hydrothermal post grafting method using TEOS as silica source and triblock poly（ethylene oxide）-b-poly（propylene oxide）-b-poly（ethylene oxide） copolymer Pluronic P123 as template, respectively with（3-Aminopropyl） triethoxy silane（APTES）、N-3-（Trimethoxysily） propyl ethylenediamine、Trimethoxysilyl Propyl Diethylenetriamias coupling agent. The synthesized mesoporous SBA-15 samples were characterized by X-ray diffraction, FTIR, N2 adsorption-desorption and SEM.The results show that the NH₂-SBA-15 synthesized by the post grafting method is more effective at adsorping Pb²⁺ in water. The more aminos are grafted, the more Pb²⁺are adsorped by the modified mesoporous materials. The best adsorptive performance occurs when the grafting percentage of diamino is between 10% to 15%.Adsorption properties and influencing factors of modified materials were studied by a large number of experiments. The experimental results indicate that the optimum pH value of the adsorption system is 5, the optimal adsorption time is 60 min and the optimal adsorption temperature is 40℃.