Uranium adsorption studies on aminopropyl modified mesoporous sorbent (NH2–MCM-41) using statistical design method

Functionalized magnetic mesoporous silica nanoparticles for U removal from low and high pH groundwater

“…Functionalized mesoporous silica nanomaterials have been developed and demonstrated as effective sorbents for the removal of organic and inorganic pollutants [4][5][6][7][8], such as toxic metal anions (e.g., CrO 4 2− and AsO 4 3− ) [6], lanthanides [9,10] and actinides (e.g., Pu [11,12], Np [11], and U [11][12][13][14][15][16][17][18][19][20][21][22][23][24]). For example, "Hard Lewis base" ligands (e.g., salicylic acid, glycine, phosphine ligands) incorporated as self-assembled monolayers on mesoporous supports (SAMMS) are effective for selective removal of "Hard Lewis acid" lanthanides [9,10] and actinides (e.g., Am, Pu, U and Th) [12]; while hydroxypyridinones (HOPO)-SAMMS performed well for the selective sequestration of actinides (Pu, Np, and U) [11].…”

“…For example, "Hard Lewis base" ligands (e.g., salicylic acid, glycine, phosphine ligands) incorporated as self-assembled monolayers on mesoporous supports (SAMMS) are effective for selective removal of "Hard Lewis acid" lanthanides [9,10] and actinides (e.g., Am, Pu, U and Th) [12]; while hydroxypyridinones (HOPO)-SAMMS performed well for the selective sequestration of actinides (Pu, Np, and U) [11]. In addition, there are several functionalized mesoporous silica nanoparticles that have been shown to be effective at binding aqueous U, including aminomodified MCM-41 [13] and SBA-15 [21], dopamine-functionalized SBA-15 [24], amidoxime-modified MCM-41 [23][24][25][26] and quartz [27], dihydroimidazole functionalized SBA-15 [15], monoamide resins with porous silica support [28], phosphonate or phosphine oxide-incorporated MCM-41 [16,23], SBA-V [17], KIT-6 [18] and carboxymethylated polyethyleneimine functionalized MSU-H [29]. However, among these studies, most of the functionalized mesoporous silica nanoparticles were evaluated under near-neutral pH conditions (pH [5][6][7][8] in which aqueous U species tend to precipitate or strongly adsorb onto various sorbents.…”

Preparation and adsorption performance of 5-azacytosine-functionalized hydrothermal carbon for selective solid-phase extraction of uranium

“…Among common SPE adsorbents used nowadays for separation of metal ions such as carbonaceous adsorbents [8][9][10], other inorganic adsorbents [11,12], polymeric adsorbents [13,14], biosorbents [15,16] and composite adsorbents [17][18][19], the composite adsorbents that consist specifically of a carrier matrix and functional ligands possess essentially a higher selectivity and capacity toward target metal ions over the others. The superiority in metal selectivity mediated by specific metal-ligand interactions based on its chosen building blocks makes the particular kind of adsorbent more practical and economical [19,20].…”

A heterogeneous mesoporous silica-supported cyclopentadienyl ruthenium(II) complex catalyst for selective hydrosilylation of 1-hexyne at room temperature

“…As for the complex 7, its MALDI-TOF-MS spectrum showed a peak at 289.58, which is in a good agreement with molecular weight of the final complex after losing a PF 6 − anion, i.e., C 12 showed obvious bands at 3371 and 3306 cm −1 assigned to asymmetric and symmetric NH 2 stretching modes, respectively, and also at 1594 cm −1 assigned to an NH 2 bending mode [22], which were not observed before silylation reaction. Besides, strong vibration bands at 2935 and 2870 cm −1 corresponding to CH 2 groups of the spacer connecting the alkyl group to the mesoporous silica walls were also recorded [23][24][25].…”