Herein, we report the performances of crosslinked facilitated transport membranes based on carboxymethylated nanofibrils of cellulose (cmNFC) and polyvinylamine (PVAm) with the use of 3-(2-Aminoethylamino) propyltrimethoxysilane (AEAPTMS) as second fixed carrier for CO₂ selectivity and permeability. The grafting of AEAPTMS on cmNFC was optimized by following the hydrolysis/condensation kinetics by ²⁹Si Nuclear Magnetic Resonance (NMR) analyses and two different strategies of the process of membrane production were investigated. In optimized conditions, around 25% of the -COOH functions from cmNFC have crosslinked with PVAm. The crosslinked membranes were less sensitive to liquid water and the crystallinity of PVAm was tuned by the conditions of the membrane elaboration. In both processes, CO₂ selectivity and permeability were enhanced especially at high water vapor concentration by the use of PVAm and AEAPTMS suggesting the existence of a facilitation effect due to amine-CO₂ interaction, while the mechanical integrity of the swollen membranes remained intact.

Lignin is an aromatic biopolymer derived from lignocellulosic biomass. Providing a comprehensive structural analysis of lignin is the primary motivation for the quantification of various functional groups, with a view to valorizing lignin in a wide range of applications. This study investigated the lignin fluorobenzylation reaction and performed a subsequent ¹⁹F-NMR analysis to quantify hydroxyl groups, based on a work developed two decades ago by Barrelle et al. The objectives were to check the assignments proposed in this previous study and to examine the reactivity of various types of lignin hydroxyls with the derivatization agent. Selected lignin model compounds containing phenolic and aliphatic hydroxyls were subjected to the fluorobenzylation reaction, and the obtained reaction medium was analyzed by ¹³C and ¹⁹F NMR spectroscopy. The model compound results showed that phenolic hydroxyls were totally derivatized, whereas aliphatic hydroxyls underwent minimal conversion. They also confirmed that ¹⁹F NMR chemical shifts from −115 ppm to −117.3 ppm corresponded to phenolic groups. Then, a ¹⁹F NMR analysis was successfully applied to Organosolv commercial lignin after fluorobenzylation in order to quantify its phenolic group content; the values were found to be in the range of the reported values using other analytical techniques after lignin acetylation.