Han D, Li X, Cui Y, Yang X, Chen X, Xu L, Peng J, Li J, Zhai M. Polymeric ionic liquid gels composed of hydrophilic and hydrophobic units for high adsorption selectivity of perrhenate.
RSC Adv 2018;
8:9311-9319. [PMID:
35541890 PMCID:
PMC9078687 DOI:
10.1039/c8ra00838h]
[Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 02/26/2018] [Indexed: 11/21/2022] Open
Abstract
The removal of TcO4− from aqueous solutions has attracted more and more attention recently, and ReO4− has been widely used as its natural analog. In this work, polymeric ionic liquid gel adsorbents, PC2-C12vimBr, with high adsorption capacity and selectivity towards ReO4− were synthesized by radiation-induced polymerization and crosslinking. PC2-C12vimBr was composed of two monomers: a hydrophobic unit, 1-vinyl-3-dodecylimidazolium bromide for high selectivity, and a hydrophilic unit, 1-vinyl-3-ethylimidazolium bromide for improved kinetics. A gel fraction up to 90% could be achieved under 40 kGy with varied monomer ratios. The adsorption of PC2-C12vimBr gels for ReO4− was evaluated by batch adsorption. The PC2-C12vimBr gel containing 20 mol% hydrophilic unit (named PC2-C12vimBr-A) could significantly improve the adsorption kinetics, which had an equilibrium time of ca. 24 h. The adsorption capacity obtained from the Langmuir model was 559 mg g−1 (Re/gel). The selective factor against NO3− was 33.4 ± 1.9, which was more than 10 times higher than that of PC2vimBr, and it could maintain ReO4− uptake as high as 100 mg g−1 in 0.5 mol kg−1 HNO3. The ΔHΘ and ΔSΘ of the NO3−/ReO4− ion-exchange reaction of PC2-C12vimNO3-A were −16.9 kJ mol−1 and 29 J mol−1 K−1, respectively, indicating physical adsorption. The adsorption mechanism of ReO4− onto PC2-C12vimBr-A gel was ion-exchange, and it could be recovered using 5.4 mol kg−1 HNO3.
Polymeric ionic liquid gels composed of hydrophilic and hydrophobic units with high adsorption selectivity towards perrhenate were synthesized.![]()
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