Microwave Irradiation-Assisted Synthesis of a Novel Crown Ether Crosslinked Chitosan as a Chelating Agent for Heavy Metal Ions (M+n)

Molecules

Awwad A. Radwan¹  Fars K. Alanazi¹ 

[1] ¹College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia

关键词: chitosan;    crown ether;    adsorption;   

DOI  :  10.3390/molecules15096257

来源: mdpi

【 摘 要 】

Microwave irradiation was used to obtain a di-Schiff base type crosslinked chitosan dibenzocrown ether (CCdBE) via the reaction between the –NH₂ and –CHO groups in chitosan and 4,4′-diformyldibenzo-18-c-6, respectively. The structure of the synthesized compound was characterized by elemental analysis, solid state ¹³C-NMR and FT-IR spectra analysis. The results showed that the mass fraction of nitrogen in the CCdBE derivative was much lower than those of chitosan. The FT-IR spectra of CCdBE revealed the expected chitosan-crown ether structure, as evidenced by the presence of the characteristic C=N and Ar peaks. The adsorption properties of CCdBE for Pd²⁺ and Hg²⁺ were investigated and the results demonstrated that the adsorbent has both desirable adsorption properties with a high particular adsorption selectivity for Hg²⁺ when in the presence of Pb²⁺ as well as selectivity coefficients for metal ions of K_Hg²⁺ _/Pb²⁺ = 8.00 and K_Hg ²⁺_/Pb²⁺ = 10.62 at pH values of 4 and 6, respectively. The reusability tests for CCdBE for Pb²⁺ adsorption showed that complete recovery of the ion was possible with CCdBE after 10-multiple reuses while CTS had no reusability at acidic solution because of its higher dissolution. The studied features of CCdBE suggested that the material could be considered as a new adsorbent. It is envisaged that the crosslinking of CTS into CCdBE would enhance practicality and effectiveness of adsorption in ion separation and removal procedures.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.