Rapid and Protective Dissolution of Cellulose via Hydrophobicity-Engineered Amphiphilic Ionic Liquids

With the increasing global demand for sustainable polymers, scalable routes that convert cellulosic feedstocks into high-performance materials are urgently needed. However, efficient dissolution and regeneration of cellulose (CEL) without sacrificing its native degree of polymerization (DP) remain a central challenge in the processing of cellulosic materials. Here, we introduce a hydrophobic-engineered amphiphilic ionic-liquids (AILs) platform that meets this goal. A homologous series of AILs was synthesized by grafting n-alkyl chains of tunable length onto a superbase cation. The resulting AILs dissolve CEL up to 5 times faster than state-of-the-art imidazolium ionic liquids while preserving DP values close to those of the native polymer. Long-time scale (300 ns) molecular-dynamics simulations reveal that the hydrophobic tail of the cation blankets glycosidic linkages against chain scission, whereas the ionic component disrupts inter- and intrachain hydrogen bonds to promote dissolution. This gentle and efficient processing method lowers energy demand and chemical waste, thereby reducing the environmental footprint of biobased material production. By leveraging designable, recyclable AILs, it adheres to green-chemistry principles and supports a circular materials economy. These findings reveal that the amphiphilicity tuning of ionic liquids could be applied as a practical design principle for gentle and efficient processing of sustainable biobased materials.