Table 2.
Characteristics of processes for the production of cellulose hydrogels using organic solvents.
| Solvent | Pre-Treatment of Cellulose | Dissolution Process | Gelation Process | Price * | Toxicity |
|---|---|---|---|---|---|
| DMAc/LiCl | solvent exchange (not compulsory) |
25–80 °C | humid ambient condition | 161 GBP/L (+28 GBP/100 g for LiCl) |
harmful, flammable |
| DMSO/LiCl | ball-milling complexation |
65–70 °C | ethanol, cross-linking | 89 GBP/L (+28 GBP/100 g for LiCl) |
non-toxic, flammable |
| NMMO | - | 110 °C, −0.1 MPa | 110 °C, −0.1 MPa | 1110 GBP/kg | low toxic, non- flammable |
| NaOH/water | hydrothermal, steam explosion, chemical, or enzymatic treatment | (−20)–0 °C, addition of urea/ thiourea |
cross-linking (not compulsory), cooling (approximately 0 °C) | 35 GBP/kg | non-toxic, non- flammable |
* The price is given in this study only for the purpose of an approximate comparison of reagents with each other, available online: www.fishersci.co.uk, accessed on 29 January 2023.