Integrated Nanofibrillation and In Situ Polymerization of Biomass-Deep Eutectic Solvent System—A One-Pot Approach

The employment of natural polymers such as cellulose in the synthesis of advanced materials, utilizing environmentally conscious approaches, represents a promising trajectory towards a sustainable future. Deep Eutectic Solvents (DESs) act as an emerging green solvent system with numerous capabilities in biomass pretreatment and polymer synthesis owing to its vast tunability in the selection of hydrogen bond donor and acceptor systems. In this study, a ternary DES system (choline chloride, citric acid, and acrylic acid) is utilized to facilitate the acidic condition for biomass nanofibrillation with subsequent polymerization using the acrylic monomers in one-pot approach. This process eliminates the extra steps and waste produced during commercial cellulose nanofiber generation and enables the assembly of nanofibers to generate eutectogel material. The selected novel polymerizable DES system produces cellulose nanofibers with diameters in the range of 1-30 nm while preserving its crystalline structure. Stable dispersions of the biomass-containing system were evident with the esterification of the cellulose hydroxyl groups after the DES treatment. The addition of biomass allows the composite to exhibit a yield point and achieve shear-thinning behavior, which is necessary for direct ink writing (DIW) 3D printing applications. This procedure opens up new possibilities for environmentally friendly processing of biomass materials with printable properties.