College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China.
College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China; State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory for Catalytic Conversion of Carbon Resources, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Int J Biol Macromol. 2024 Apr;264(Pt 2):130775. doi: 10.1016/j.ijbiomac.2024.130775. Epub 2024 Mar 11.
There have been continuous quests for suitable solvents for starch, given the importance of effective starch dissolution in its modification and subsequent materials production. In light of this, the potential of hydroxyl-functionalized ionic liquid (IL) as a promising solvent for starch was investigated. Within this study, a hydroxyl-functionalized IL 1-(2,3-dihydroxypropyl)-3-methylimidazole chloride ([Dhpmim][Cl]) was synthesized, and the dissolution of starch in this IL and its aqueous solutions was examined. Starch (5.35 wt%) was completely dissolved in [Dhpmim][Cl] within 2 h at 100 °C. The solubility of starch in [Dhpmim][Cl]-water mixtures initially increased and then decreased with rising water content. The optimal ratio was found to be 1:9 (wt/wt) water:[Dhpmim][Cl], achieving the highest solubility at 9.28 wt%. Density functional theory (DFT) simulations elucidated the possible interactions between starch and solvents. After dissolution and regeneration in the 1:9 water:[Dhpmim][Cl] mixture, starch showed no discernible change in the molecular structure, with no derivatization reaction observed. Regenerated starch exhibited a transformation in crystalline structure from A-type to V-type, and its relative crystallinity (12.4 %) was lower than that of native starch (25.2 %), resulting in decreased thermal stability. This study suggests that the hydroxyl-functionalized IL, [Dhpmim][Cl], and its aqueous solutions serve as effective solvents for starch dissolution.
鉴于有效溶解淀粉对其改性和后续材料生产的重要性，人们一直在不断寻找合适的溶剂。有鉴于此，本研究考察了羟基功能化离子液体（IL）作为淀粉有前途的溶剂的潜力。在本研究中，合成了一种羟基功能化 IL 1-(2,3-二羟丙基)-3-甲基咪唑氯化物([Dhpmim][Cl])，并研究了淀粉在该 IL 及其水溶液中的溶解情况。在 100°C 下，淀粉（5.35wt%）在 2 小时内完全溶解于[Dhpmim][Cl]中。淀粉在[Dhpmim][Cl]-水混合物中的溶解度最初随含水量的增加而增加，然后降低。发现最佳比例为 1:9（wt/wt）水：[Dhpmim][Cl]，在 9.28wt%时溶解度最高。密度泛函理论（DFT）模拟阐明了淀粉与溶剂之间可能的相互作用。在 1:9 水：[Dhpmim][Cl]混合物中溶解和再生后，淀粉的分子结构没有明显变化，没有观察到衍生化反应。再生淀粉的结晶结构从 A 型转变为 V 型，其相对结晶度（12.4%）低于天然淀粉（25.2%），导致热稳定性降低。本研究表明，羟基功能化 IL [Dhpmim][Cl]及其水溶液是溶解淀粉的有效溶剂。
