Ordered SBA-15 mesoporous silica with high amino-functionalization for adsorption of heavy metal ions  

作　　者：ZHANG Dan LI JunHua 

机构地区：[1]School of Chemistry and Environmental Engineering, Liaoning University of Technology

出　　处：《Chinese Science Bulletin》2013年第8期879-883,共5页

摘　　要：Surface NH2 -functionalized SBA-15 mesoporous silica was synthesized using toluene diisocyanate (TDI) as a bridge molecule. First, the surface Si-OH groups of SBA-15 were reacted with the -NCO groups of TDI. Then, the remaining unreacted -NCO groups of TDI were reacted with the -NH2 groups of ethylenediamine (EDA). Finally, the NH2 -groups were successfully grafted onto the mesoporous SBA-15 surface by the above two-step method. XRD, N2 adsorption-desorption analysis, FT-IR, and 29 Si MAS NMR were used to identify the well-ordered structure and the successful incorporation of the -NH2 groups onto the surface of the synthesized materials. Characterizations revealed that such -NH2 grafting is an effective method to obtain a high loading of -NH2 groups onto the SBA-15. When subjected to toxic heavy metal ions in aqueous solution, the obtained NH 2 -functionalized SBA-15 showed very high adsorption rates 99.9%, 99.7%, 99.8%, 99.5% and 99.9% for Pb2+ , Cr3+ , Cd2+ , Ag+ and the Cu2+ , respectively, which is attributed to the strong complexation reactions between the metal ions and the grafted -NH2 groups.Surface NH2-functionalized SBA-15 mesoporous silica was synthesized using toluene diisocyanate （TDI） as a bridge molecule. First, the surface Si-OH groups of SBA-15 were reacted with the -NCO groups of TDI. Then, the remaining unreacted -NCO groups of TDI were reacted with the -NH2 groups of ethylenediamine （EDA）. Finally, the NH2-groups were successfully grafted onto the mesoporous SBA-15 surface by the above two-step method. XRD, N2 adsorption-desorption analysis, FF-IR, and 298i MAS NMR were used to identify the well-ordered structure and the successful incorporation of the -NH2 groups onto the surface of the synthesized materials. Characterizations revealed that such -NH2 grafting is an effective method to obtain a high loading of -NH2 groups onto the SBA-15. When subjected to toxic heavy metal ions in aqueous solution, the obtained NH2-functionalized SBA-15 showed very high adsorption rates 99.9%, 99.7%, 99.8%, 99.5% and 99.9% for Pb2＋, Cr3＋, Cd2＋, Ag＋ and the Cu〉, respectively, which is attributed to the strong complexation reactions between the metal ions and the grafted -NH2 groups.

关 键 词：SBA-15 介孔二氧化硅 重金属离子 吸附率 氨基 功能化 NCO基团 甲苯二异氰酸酯 

分 类 号：Q78[生物学—分子生物学]