The adsorption aspect of Cu2 + and Zn2 + on MCM-41 and SDS-modified MCM-41

This study performed both macroscopic and microscopic investigation to determine the interaction mechanism for heavy metal adsorption on functionalized MCM-41 mesoporous silica. Hybrid sorbent material has been developed by modifying MCM-41 with sodiumdodecylsulphate (SDS), named as SDS-MCM-41, and tested for capturing Cu2+ and Zn2+ in the solution. Zeta potentials of pristine MCM-41, SDS-MCM-41, and the adsorbents that adsorbed Cu2+ and Zn2+ for different pHs and initial metal ion concentrations were employed to estimate macroscopically the adsorption ability. Molecular dynamics (MD) simulation was performed to investigate adsorption behavior in microscopic point of view. Zeta potential and molecular simulation reveal that SDS functional groups are responsible for the adsorption of metal ions through the interaction between the anionic charged surface of SDS-MCM-41 and the cationic metal ions. The qualitatively consistent results of molecular dynamics simulations with experiments suggest the possibility of applying computer simulation for preliminarily selection of adsorbent functional groups for removal of Cu2+ and Zn2+.