The present study investigated the novel amine-functionalized cellulose/chitosan (Ce/Cs) composite materials for efficient carbon dioxide (CO2) adsorption. Cellulose (Ce) was chemically modified by tetraethylenepentamine (TEPA) functionalization and subsequently blended with chitosan (Cs) to enhance the composite's CO2 capture capability. Characterization techniques, including Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), N2 adsorption-desorption, and field emission scanning electron microscopy (FESEM), confirmed successful amine incorporation, composite formation, and a well-defined mesoporous structure. Experimental optimization revealed that a TEPA loading of 15 wt% coupled with a Ce-to-Cs mass ratio of 3:1 provided optimal CO2 adsorption performance. Under 25 °C and 9 bar, Ce3-TEPA15%/Cs1 reached a maximum experimental CO2 uptake of 358.44 mg g-1, compared with 270 mg g-1 for Ce3Cs1. Adsorption isotherms and kinetics data were best fitted by the Freundlich model with R2 of 0.999 and the fractional-order kinetic model with R2 of 0.863-0.986, indicating favorable and heterogeneous adsorption. Thermodynamic results (ΔH° ≈ -23.94 kJ mol-1) confirmed an exothermic process and supported a mixed physisorption/chemisorption mechanism. The optimized composite also showed good regenerability, retaining ~92% of its initial capacity after 10 adsorption-desorption cycles under mild regeneration (~40 °C). Overall, the combination of covalent amine anchoring and a bio-based matrix provides a practical route to efficient, reusable sorbents for CO2 capture.
Panahi et al. (Mon,) studied this question.