Efficient adsorption of flavonoids on amino-functionalized ZIF-8/chitosan aerogels

• Published in: International journal of biological macromolecules Vol. 282; no. Pt 2; p. 136928
• Main Authors: Zhang, Feiyue, Ma, Ning, He, Lingxiao, Lin, Hanchen, Wei, Shuangyu, Zhao, Xinxu, You, Chaoqun, Cai, Lingchao, Wang, Fei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2024
• Subjects: Aerogel; Amino-ZIF-8; Chitosan; Flavonoids; Isolation purification; Flavonoids; Isolation purification; Chitosan; Aerogel; Amino-ZIF-8
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.136928

Covalent organic structures (MOFs), known for their exceptional properties in separation and purification, have garnered significant attention. However, applying MOF-based adsorbents in complex flavonoid separation scenarios remains challenging. In this study, we successfully synthesized adsorbent materials capable of efficiently adsorbing flavonoids using a vacuum freeze-drying method. The materials were derived from a cross-linked chitosan aerogel functionalized with amino-substituted zeolite imidazolium ester skeleton (ZIF-8). The ZIF-8-NH2, synthesized via in situ substitution of 2-aminobenzimidazole within the ZIF-8 framework, exhibits a smaller pore size than mono ligand ZIF-8. Due to its synergistic interaction with chitosan's biocompatibility and porous structure, the aerogel material (ZIF-8-NH2/CS) exhibited outstanding adsorption capacities (183.37 mg/g, 226.34 mg/g, and 187.16 mg/g) in standard solutions (T = 318 K, rpm = 200) of luteolin, quercetin, and rutin, along with high adsorption rates (71.3 ± 2.3 %, 72.4 ± 1.4 %, and 70.7 ± 3.5 %). And showed rapid adsorption in the first 60 min. After 5 cycles, the adsorption capacity of ZIF-8-NH2/CS aerogel remained at 80.5 % of the adsorption capacity of the initial cycle, and therefore, ZIF-8-NH2/CS aerogel has a good potential for reusability. Additionally, the adsorption process adhered to pseudo-first-order and pseudo-second-order kinetic models, alongside Langmuir and Freundlich isothermal adsorption models. This study introduces novel ideas and methods for the extraction and separation of flavonoids. Furthermore, the developed ZIF-8-NH2/CS aerogels with amino functionality hold promise for diverse applications in separating and purifying bioactive substances. •Aerogel designed with affinity for flavonoids using vacuum freeze-drying strategy•ZIF-8-NH2/CS exhibits excellent adsorption properties and excellent adsorption selectivity.•The synergistic effect of the interaction between ZIF-8-NH2 and CS enhanced the affinity for flavonoids.