Hypothesis: The expansion of numerous industries has rendered CO₂ separationa critical challenge in contemporary society. Among the diverse techniques employed for CO₂ separation, membrane separation has emerged as a
promising and effective approach. Notably, membranes composed of polyether block amide (Pebax) are among the most prevalent and utilized in industrial applications However, despite their extensive applications, the trade-off limitation remains a significant obstacle associated with this polymer-based membrane technology prompting extensive research efforts aimed at addressing this issue in recent years In this research, cellulose was employed to address the trade-off limitation associated with Pebax membranes. Cellulose was first subjected to carboxylation before being incorporated into the polymer matrix
Methods: The presence of hydroxyl groups in cellulose facilitates improved interaction between the membrane matrix and CO₂, while simultaneously enhancing the mechanical strength of the resulting membrane through the formation of hydrogen bonds. To enhance the miscibility of cellulose with Pebax, the cellulose was first subjected to carboxylation before being incorporated into the polymer solution
Findings: The incorporation of carboxylated cellulose into Pebax resulted in an increase in the stiffness of the membrane matrix, attributed to the formation of hydrogen bonds between the cellulose and Pebax chains. This modification led to a notable enhancement in separation performance, with CO₂/N₂ selectivity for the P3C1 and P2C1 membranes rising by 92% and 120%, respectively, in comparison to the pure membrane. The enhancement in membrane performance facilitated these membranes in surpassing the Robeson limit and addressing the trade-off limitation underscoring the significant contribution of this commonly utilized material in augmenting the separation efficiency of Pebax. Furthermore, assessments of the mechanical strength of the membranes revealed a 5-fold increase in Young's modulus and a 3.5-fold enhancement in the tensile strength of the P2C1 membrane relative to the pure membrane.