Covalent crosslinking tetraethylenepentamine/cellulose composite aerogels with adsorbability for dye elimination

Abstract

The cellulose-biomass material possesses a distinctive structure, distinguished by its eco-friendliness, degradability, renewability, cost-effectiveness, and efficacy as a bio-absorbent. In this groundbreaking study, we synthesized cellulose aerogels for the first time using a combination of sol-gel processing, straightforward chemical crosslinking, and freeze-drying. The functionalized materials exhibit an intricately interconnected three-dimensional porous structure achieved through covalent crosslinking with tetraethylenepentamine (TEPA). The resulting aerogel demonstrated a highly porous structure (exceeding 90%), low density (91.89–114.87 mg/cm3), and abundant surface amine groups advantageous for removing organic dyestuffs. To comprehensively assess the impact of the fabricated aerogel on methylene blue and crystal violet adsorption behavior, a detailed investigation was conducted, considering variables such as cellulose content (1.0–3.0 wt%), TEPA/EtOH/H2O volume ratio (1.0–3.0/5.0/3.0), contact time (0–300 min), and initial dye concentration (25–200 mg/L). As a result, the nitrogen-rich aerogel (with 2 wt% cellulose and TEPA/EtOH/H2O ratio of 2.0/5.0/3.0) exhibited dye adsorption following a pseudo-second-order kinetic model, with adsorption isotherms aligning with the Freundlich model. Thermodynamic assessments indicated that the adsorption process is a spontaneous endothermic reaction. Consequently, these eco-friendly cellulose sponges emerge as promising adsorbents for effective wastewater treatment, highlighting their potential as a sustainable solution in environmental remediation.