Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions
In this work, we prepared highly swelling, stimuli-responsive hydrogels capable of the highly efficient adsorption of inorganic pollutants. The hydrogels were based on hydroxypropyl methyl cellulose (HPMC) grafted with acrylamide (AM) and 3-sulfopropyl acrylate (SPA) and were synthesized via the gro...
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| Format: | Article |
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MDPI AG
2023-04-01
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| Series: | Gels |
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| Online Access: | https://www.mdpi.com/2310-2861/9/4/296 |
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| author | Hebat-Allah S. Tohamy Mohamed El-Sakhawy Beata Strachota Adam Strachota Ewa Pavlova Silvia Mares Barbosa Samir Kamel |
| author_facet | Hebat-Allah S. Tohamy Mohamed El-Sakhawy Beata Strachota Adam Strachota Ewa Pavlova Silvia Mares Barbosa Samir Kamel |
| author_sort | Hebat-Allah S. Tohamy |
| collection | DOAJ |
| description | In this work, we prepared highly swelling, stimuli-responsive hydrogels capable of the highly efficient adsorption of inorganic pollutants. The hydrogels were based on hydroxypropyl methyl cellulose (HPMC) grafted with acrylamide (AM) and 3-sulfopropyl acrylate (SPA) and were synthesized via the growth (radical polymerization) of the grafted copolymer chains on HPMC, which was activated by radical oxidation. These grafted structures were crosslinked to an infinite network by a small amount of di-vinyl comonomer. HPMC was chosen as a cheap hydrophilic and naturally sourced polymer backbone, while AM and SPA were employed to preferentially bond coordinating and cationic inorganic pollutants, respectively. All the gels displayed a pronounced elastic character, as well as considerably high values of stress at break (several hundred %). The gel with the highest fraction of the ionic comonomer SPA (with an AM/SPA ratio = 0.5) displayed the highest equilibrium swelling ratio (12,100%), the highest volume response to temperature and pH, and the fastest swelling kinetics, but also the lowest modulus. The other gels (with AM/SPA = 1 and 2) displayed several times higher moduli but more modest pH responses and only very modest temperature sensitivity. Cr(VI) adsorption tests indicated that the prepared hydrogels removed this species from water very efficiently: between 90 and 96% in one step. The hydrogels with AM/SPA ratios of 0.5 and 1 appeared to be promising regenerable (via pH) materials for repeated Cr(VI) adsorption. |
| first_indexed | 2024-03-11T05:00:19Z |
| format | Article |
| id | doaj.art-a4b618c608944b57a9e71dc8f074ad67 |
| institution | Directory Open Access Journal |
| issn | 2310-2861 |
| language | English |
| last_indexed | 2024-03-11T05:00:19Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Gels |
| spelling | doaj.art-a4b618c608944b57a9e71dc8f074ad672023-11-17T19:21:26ZengMDPI AGGels2310-28612023-04-019429610.3390/gels9040296Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous SolutionsHebat-Allah S. Tohamy0Mohamed El-Sakhawy1Beata Strachota2Adam Strachota3Ewa Pavlova4Silvia Mares Barbosa5Samir Kamel6Cellulose & Paper Department, National Research Centre, 33 El-Bohouth St., Dokki, Giza 12622, EgyptCellulose & Paper Department, National Research Centre, 33 El-Bohouth St., Dokki, Giza 12622, EgyptInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Praha, Czech RepublicInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Praha, Czech RepublicInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Praha, Czech RepublicInstitute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 00 Praha, Czech RepublicCellulose & Paper Department, National Research Centre, 33 El-Bohouth St., Dokki, Giza 12622, EgyptIn this work, we prepared highly swelling, stimuli-responsive hydrogels capable of the highly efficient adsorption of inorganic pollutants. The hydrogels were based on hydroxypropyl methyl cellulose (HPMC) grafted with acrylamide (AM) and 3-sulfopropyl acrylate (SPA) and were synthesized via the growth (radical polymerization) of the grafted copolymer chains on HPMC, which was activated by radical oxidation. These grafted structures were crosslinked to an infinite network by a small amount of di-vinyl comonomer. HPMC was chosen as a cheap hydrophilic and naturally sourced polymer backbone, while AM and SPA were employed to preferentially bond coordinating and cationic inorganic pollutants, respectively. All the gels displayed a pronounced elastic character, as well as considerably high values of stress at break (several hundred %). The gel with the highest fraction of the ionic comonomer SPA (with an AM/SPA ratio = 0.5) displayed the highest equilibrium swelling ratio (12,100%), the highest volume response to temperature and pH, and the fastest swelling kinetics, but also the lowest modulus. The other gels (with AM/SPA = 1 and 2) displayed several times higher moduli but more modest pH responses and only very modest temperature sensitivity. Cr(VI) adsorption tests indicated that the prepared hydrogels removed this species from water very efficiently: between 90 and 96% in one step. The hydrogels with AM/SPA ratios of 0.5 and 1 appeared to be promising regenerable (via pH) materials for repeated Cr(VI) adsorption.https://www.mdpi.com/2310-2861/9/4/296cellulose-based hydrogelsgraft copolymerizationstimuli-sensitive hydrogelsCr(VI) adsorptionswelling kinetics |
| spellingShingle | Hebat-Allah S. Tohamy Mohamed El-Sakhawy Beata Strachota Adam Strachota Ewa Pavlova Silvia Mares Barbosa Samir Kamel Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions Gels cellulose-based hydrogels graft copolymerization stimuli-sensitive hydrogels Cr(VI) adsorption swelling kinetics |
| title | Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions |
| title_full | Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions |
| title_fullStr | Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions |
| title_full_unstemmed | Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions |
| title_short | Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions |
| title_sort | temperature and ph responsive super absorbent hydrogel based on grafted cellulose and capable of heavy metal removal from aqueous solutions |
| topic | cellulose-based hydrogels graft copolymerization stimuli-sensitive hydrogels Cr(VI) adsorption swelling kinetics |
| url | https://www.mdpi.com/2310-2861/9/4/296 |
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