EDTA Modified Hollow Microporous Organic Nanospheres for Enhancing Adsorption of Metal Ions

In this study, ethylenediaminetetraacetic acid (EDTA) modified hollow microporous organic nanospheres (EDTA-HMONs-BA) were prepared by a combination of one-pot hyper-crosslinking mediated self-assembly using polylactide-b-polystyrene (PLA-b-PS) diblock copolymer and benzylamine (BA) monomers as precursors and subsequent post-modification with EDTA. The obtained EDTA-HMONs-BA were characterized by FT-IR, TEM, TGA, solid state C-13 NMR, N-2 adsorption-desorption test et al. It revealed that the EDTA-HMONs-BA have a high specific surface area (226.86 m(2) g(-1)), which exhibited excellent adsorption ability for Cu2+ ions (236 mg g(-1)) with adsorption characteristics of pseudo-second-order model and Langmuir isotherm equation. Moreover, the obtained adsorbent is of high stability after five consecutive cycles. Besides, EDTA-HMONs-BA also showed good adsorption capacities for hard acid metal ions (Cr3+), soft acid metal ions (Ag+, Cd2+), borderline acid metal ions (Cu2+, Ni2+, Zn2+). The above results indicated that the EDTA-HMONs-BA can be considered as potential adsorbents for the removal of heavy-metal ions owing to the easily accessible adsorption sites and sufficiently good stability.

Automated summary

In this study, EDTA modified hollow microporous organic nanospheres were prepared and exhibited excellent adsorption capacity and high stability for heavy-metal ions.