Zwitterionic hybrid aerobeads of binary metal organic frameworks and cellulose nanofibers for removal anionic pollutants

• Published in: Materials & design Vol. 196; p. 109106
• Main Authors: KarzarJeddi, Mohammad, Laitinen, Ossi, Mahkam, Mehrdad, Liimatainen, Henrikki
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2020; Elsevier
• Subjects: Aerogel; Diclofenac; Metal organic frameworks; Methyl orange; Nanocellulose; Nanocellulose; Metal organic frameworks; Methyl orange; Aerogel; Diclofenac
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2020.109106

Different adsorbents have been applied to remove various anionic pollutants in water treatment processes. However, the development of economic, sustainable, and high-performance adsorbents is still a challenge. Herein, we introduce a new strategy to produce highly porous (98.96%), very low density (0.015 g/cm3), and cost-effective spherical and nanostructured hybrid aerogels, termed aerobeads, from cellulose nanofibers (CNF) and metal-organic frameworks (MOFs). The zwitterionic MOFs@CNF aerobeads (with 10–50 wt% MOF loading) were synthesized via simple dropping of a cross-linked hydrogel containing CNF and a binary mixture of anionic and cationic MOFs in liquid nitrogen, followed by freeze-drying. The flexible aerobeads (diameter of 2–3 mm) with hierarchical porous structure demonstrated an outstanding adsorption capacity toward both diclofenac (121.20 mg/g) and methyl orange (49.21 mg/g). Moreover, the aerobeads were easily collected after use from the solution without any complicated separation methods or the formation of secondary pollutants.
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•A novel freeze-drying approach for fabrication of functional, highly porous nanocellulose aerobeads was introduced.•Zwitterionic aerobeads were obtained by mixing of anionic (HKUST-1) and cationic (ZIF-67) MOFs in nanocellulose framework.•The aerobeads showed an outstanding adsorption toward both diclofenac (121.20 mg/g) and methyl orange (49.21 mg/g).