Polar zwitterion/saccharide-based deep eutectic solvents for cellulose processing

Hydrogen bond reconstruction strategy for eutectic solvents that realizes room-temperature dissolution of cellulose

“…17 Sharma et al proposed polar zwitterion/saccharide-based DESs for successful cellulose dissolution as well as one-pot ethanol production. 18 Recently, a metal salt hydrate-based deep eutectic solvent composed of zinc chloride (ZnCl 2 ), phosphoric acid and water has been demonstrated to be a promising solvent for room-temperature dissolution of cellulose due to its strong HB accepting ability. 19 Almost simultaneously, a green and recyclable AlCl 3 /ZnCl 2 aqueous system was proposed for cellulose dissolution at room temperature.…”

History repeats itself again: Will the mistakes of the past for ILs be repeated for DESs? From being considered ionic liquids to becoming their alternative: the unbalanced turn of deep eutectic solvents

“…Likewise, there are systems capable of dissolving cellulose and defined as “DES” in the literature whose phase diagrams have not been reported, nor do they possess the often vaunted DES properties of low toxicity, low volatility, and ease of preparation. This is the case, for instance, of “DES” systems whose HBAs are imidazole zwitterions 248 or allylammonium chlorides, 249 which require a preparation process similar to that of ILs. Another controversial example is represented by the DBU/methylthiourea mixture reported by Fu et al , 250 a system capable of dissolving cellulose and whose dissolution mechanism was investigated by quantum mechanical calculations.…”

Role of deep eutectic solvents as pretreatment medium for biomass transformation

“…Another up-to-date research was conducted by Sharma et al (2021) whereby zwitterionbased DESs have opted for cellulose dissolution and the subsequent processing. Zwitterionbased DESs were prepared by mixing four types of saccharide at various ratios.…”