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

• Main Authors: Mohammad KarzarJeddi, Ossi Laitinen, Mehrdad Mahkam, Henrikki Liimatainen
• Format: Article
• Language: English
• Published: Elsevier 2020-11-01
• Series: Materials & Design
• Subjects: Aerogel; Nanocellulose; Diclofenac; Methyl orange; Metal organic frameworks
• Online Access: http://www.sciencedirect.com/science/article/pii/S0264127520306419

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.