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Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions

It is still a challenge to develop advanced materials able to simultaneously remove more than one pollutant. Exclusive cationic composite double- and triple-network cryogels, with adequate sustainability in the removal of Cr(2)O(7)(2−) and H(2)PO(4)(−) oxyanions, were developed in this work starting...

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Autores principales: Dragan, Ecaterina Stela, Humelnicu, Doina, Dinu, Maria Valentina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9966014/
https://www.ncbi.nlm.nih.gov/pubmed/36850169
http://dx.doi.org/10.3390/polym15040885
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author Dragan, Ecaterina Stela
Humelnicu, Doina
Dinu, Maria Valentina
author_facet Dragan, Ecaterina Stela
Humelnicu, Doina
Dinu, Maria Valentina
author_sort Dragan, Ecaterina Stela
collection PubMed
description It is still a challenge to develop advanced materials able to simultaneously remove more than one pollutant. Exclusive cationic composite double- and triple-network cryogels, with adequate sustainability in the removal of Cr(2)O(7)(2−) and H(2)PO(4)(−) oxyanions, were developed in this work starting from single-network (SN) sponges. Chitosan (CS), as the only polycation originating from renewable resources, and poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA) and polyethyleneimine (PEI), as synthetic polycations, were employed to construct multi-network cationic composite cryogels. The properties of the composites were tailored by the cross-linking degree of the first network (SN5 and SN20, which means CS with 5 or 20 mole % of glutaraldehyde, respectively) and by the order of the successive networks. FTIR, SEM-EDX, equilibrium water content and compressive tests were used in the exhaustive characterization of these polymeric composites. The sorption performances towards Cr(2)O(7)(2−) and H(2)PO(4)(−) anions were evaluated in batch mode. The pseudo-first-order, pseudo-second-order (PSO) and Elovich kinetics models, and the Langmuir, Freundlich and Sips isotherm models were used to interpret the experimental results. The adsorption data were the best fitted by the PSO kinetic model and by the Sips isotherm model, indicating that the sorption mechanism was mainly controlled by chemisorption, irrespective of the structure and number of networks. The maximum sorption capacity for both oxyanions increased with the increase in the number of networks, the highest values being found for the multi-network sponges having SN5 cryogel as the first network. In binary systems, all sorbents preferred Cr(2)O(7)(2−) ions, the selectivity coefficient being the highest for TN sponges. The high sorption capacity and remarkable reusability, with only a 4–6% drop in the sorption capacity after five sorption–desorption cycles, recommend these composite cryogels in the removal of two of the most dangerous pollutants represented by Cr(2)O(7)(2−) and H(2)PO(4)(−).
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spelling pubmed-99660142023-02-26 Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions Dragan, Ecaterina Stela Humelnicu, Doina Dinu, Maria Valentina Polymers (Basel) Article It is still a challenge to develop advanced materials able to simultaneously remove more than one pollutant. Exclusive cationic composite double- and triple-network cryogels, with adequate sustainability in the removal of Cr(2)O(7)(2−) and H(2)PO(4)(−) oxyanions, were developed in this work starting from single-network (SN) sponges. Chitosan (CS), as the only polycation originating from renewable resources, and poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA) and polyethyleneimine (PEI), as synthetic polycations, were employed to construct multi-network cationic composite cryogels. The properties of the composites were tailored by the cross-linking degree of the first network (SN5 and SN20, which means CS with 5 or 20 mole % of glutaraldehyde, respectively) and by the order of the successive networks. FTIR, SEM-EDX, equilibrium water content and compressive tests were used in the exhaustive characterization of these polymeric composites. The sorption performances towards Cr(2)O(7)(2−) and H(2)PO(4)(−) anions were evaluated in batch mode. The pseudo-first-order, pseudo-second-order (PSO) and Elovich kinetics models, and the Langmuir, Freundlich and Sips isotherm models were used to interpret the experimental results. The adsorption data were the best fitted by the PSO kinetic model and by the Sips isotherm model, indicating that the sorption mechanism was mainly controlled by chemisorption, irrespective of the structure and number of networks. The maximum sorption capacity for both oxyanions increased with the increase in the number of networks, the highest values being found for the multi-network sponges having SN5 cryogel as the first network. In binary systems, all sorbents preferred Cr(2)O(7)(2−) ions, the selectivity coefficient being the highest for TN sponges. The high sorption capacity and remarkable reusability, with only a 4–6% drop in the sorption capacity after five sorption–desorption cycles, recommend these composite cryogels in the removal of two of the most dangerous pollutants represented by Cr(2)O(7)(2−) and H(2)PO(4)(−). MDPI 2023-02-10 /pmc/articles/PMC9966014/ /pubmed/36850169 http://dx.doi.org/10.3390/polym15040885 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Dragan, Ecaterina Stela
Humelnicu, Doina
Dinu, Maria Valentina
Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
title Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
title_full Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
title_fullStr Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
title_full_unstemmed Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
title_short Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
title_sort sustainable multi-network cationic cryogels for high-efficiency removal of hazardous oxyanions from aqueous solutions
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9966014/
https://www.ncbi.nlm.nih.gov/pubmed/36850169
http://dx.doi.org/10.3390/polym15040885
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