Kinetics and selectivity insights into carbon dioxide capture utilizing carboxymethyl cellulose-polypyrrole nanocomposites: Screening of silane functionalization

Cellulose is a highly versatile and abundant biopolymer that holds significant promise for enhancing capture technologies due to its inherent properties. However, to maximize its effectiveness in carbon dioxide (CO₂) adsorption, it is essential to enhance its properties through chemical or physical modifications. By developing cellulose-based materials with tailored functionalities, we can create sustainable sorbents that not only contribute to reducing greenhouse gas emissions but also leverage low-cost and environmentally friendly resources, making them suitable for large-scale applications in carbon capture technologies. This study demonstrates the synthesis of carboxymethyl cellulose-polypyrrole (CMC-PP) nanocomposite and its coating with (3-aminopropyl)triethoxysilane (APTS) or (3-mercaptopropyl)trimethoxysilane (MPTS) to derive CMC-PP-NH₂ and CMC-PP-SH nanocomposites, respectively. The designed composites' physicochemical properties were studied using various analytical techniques. The CO₂ and N₂ capture capabilities of CMC-PP, CMC-PP-NH₂, and CMC-PP-SH nanocomposites were investigated. Among them, the CMC-PP-SH nanocomposite has exhibited the highest CO₂ adsorption capacity of 49.6 cm³g⁻¹. Adsorption isotherms fitting using the dual-site Langmuir model and calculation of standard enthalpy changes (Q_st) reveal that the thiol groups in CMC-PP-SH provide the most favourable interactions for CO₂ capture. These findings demonstrate the potential utilization of silane coatings to develop advanced materials for effective gas adsorption and separation technologies.