Sustainable TOCNS/chitosan aerogels: Green synthesis, enhanced flavonoid adsorption, and recyclability for...

In response to the urgent need for highly efficient adsorbents for natural flavonoid compounds, this study proposes a novel layered porous aerogel (TOCNS@CS) based on a synergistic hydrogen bonding/electrostatic interaction mechanism. Through a green aqueous sol-gel method, TEMPO-oxidized cellulose nanocrystals (TOCNS) were cross-linked with chitosan (CS), and combined with freeze-drying technology to construct a lightweight, recyclable adsorbent material. Density functional theory (DFT) calculations revealed the synergistic adsorption pathways of carboxyl (-COOH) and amino (-NH₂) groups, enabling ultra-high selectivity in the capture of flavonoid compounds. Experiments showed that the aerogel had an adsorption capacity of 151.90 mg/g for quercetin at 318 K, surpassing traditional resin materials by 78 %, and maintained 78.95 % of its initial capacity after five cycles. This study provides a sustainable solution for flavonoid purification in food and environmental applications.