Chung, Jaeshik Chun, Jinyoung Lee, Jinwoo Lee, Sang Hyup Lee, Young Jae Hong, Seok Won 2024-01-20T13:34:06Z 2024-01-20T13:34:06Z 2021-09-05 2012-11 0304-3894 https://pubs.kist.re.kr/handle/201004/128720 Steric factors affecting the mass transfer of Pb(II) and Cu(II) in mesocellular silica foams (MSU-F-S) functionalized with multi- (mono-, di-, tri-) amine groups and nano-magnetite were investigated through batch experiments. We observed that neither the sorption capacities nor the sorption rates were linearly proportional to the number of amine groups introduced to a ligand. Unexpectedly, the tri-amine grafted samples exhibited lower affinity for both metal cations. These results are mainly attributed to two important steric factors, pore blockage and a conformational change of available amine groups. The relatively large pore size (similar to 30 nm) of MSU-F-S could enable various functional molecules such as amines and nano-magnetite to be effectively loaded within the pores. However, their excessive densities in the limited pore structure could have adverse effects on the transport of metal ions into the mesopores. An intraparticle diffusion model was applied to elucidate the mechanisms involved in the sorption process. Our results showed that the diffusional mass transfer into the mesopores was significantly inhibited in triamine grafted samples. The present findings further the understanding of steric effects on the transport of cationic metals into functionalized mesoporous silica and designing efficient sorbents. (C) 2012 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE BV Sorption of Pb(II) and Cu(II) onto multi-amine grafted mesoporous silica embedded with nano-magnetite: Effects of steric factors Article 10.1016/j.jhazmat.2012.08.063 1 JOURNAL OF HAZARDOUS MATERIALS, v.239, pp.183 - 191 JOURNAL OF HAZARDOUS MATERIALS 239 183 191 N scie scopus 000310763600023 2-s2.0-84867695247 Engineering, Environmental Environmental Sciences Engineering Environmental Sciences & Ecology Article HEAVY-METAL IONS FUNCTIONALIZED MCM-41 MOLECULAR-SIEVES ADSORPTION REMOVAL CO2 NANOPARTICLES WASTEWATERS ADSORBENTS SBA-15 Conformational change Heavy metals sorption Multi-amine grafted MSU-F-S/Fe3O4 Pore blockage Steric hindrance