Cellulose aerogel beads and monoliths from CO2-based reversible ionic liquid solution.

The CO2-based reversible ionic liquid solution of 1,1,3,3-tetramethylguanidine (TMG) and ethylene glycol (EG) in dimethyl sulfoxide (DMSO) after capturing CO2, (2[TMGH]+[O2COCH2CH2OCO2]2-/DMSO (χRILs = 0.1), provides a sustainable and effective platform for cellulose dissolution and homogeneous utilization. Highly porous cellulose aerogel beads and monoliths were successfully prepared via a sol-gel process by extruding cellulose solution into different coagulation baths (NaOH aqueous solution or alcohols) and exposing the cellulose solution in open environment, respectively, and followed by different drying techniques, including supercritical CO2-drying, freeze-drying and air-drying. The effect of the coagulation baths and drying protocols on the multi-scale structure of the as-prepared cellulose aerogel beads and monoliths were studied in detail, and the sol-gel transition mechanism was also studied by the solvatochromic parameters determination. High specific surface area of 252 and 207 m2/g for aerogel beads and monoliths were achieved, respectively. The potential of cellulose aerogels in dye adsorption was demonstrated.

Engineering chitosan into fully bio-sourced, water-soluble and enhanced antibacterial poly(aprotic/protic ionic liquid)s packaging membrane.

The design and facile preparation of water-soluble and eco-friendly polymer packaging membrane materials is a fascinating research topic, particularly in terms of the increasing concerns on potential microplastics pollution in ecosystem. In this study, taking advantages of the structural features of chitosan (CS) and betaine hydrochloride (BHC), fully bio-sourced and water-soluble poly(aprotic/protic ionic liquid)s (PAPILs) were successfully designed and prepared through the reaction of the amino groups in CS and carboxyl groups in BHC. The structure and thermo-properties of the PAPILs were elucidated by a series of characteristic methods. The rheological properties of the PAPILs aqueous solutions were also investigated. Moreover, water-soluble PAPILs membrane with a smooth surface morphology and a tensile strength of 62.9 MPa was successfully prepared. The PAPILs membrane also exhibited satisfactory biocompatibility, excellent antibacterial activities and high oxygen barrier property. Together with these outstanding material performance and functionality, as a "proof of concept", the potential use of the PAPILs membrane as water-soluble packaging material for laundry detergent capsule and pesticide was preliminarily demonstrated. These findings provide significant insights for the design of sustainable and functional packaging materials by using natural resources.