Carbohydrates-tailored phase tunable systems composed of ionic liquids and water

Carbohydrates were found to have substantial effects on tailoring phase tunable of ionic liquids (ILs) and water. Phase behaviors of 1-alkyl-3-methylimidazolium derivatives [C(n)mim]X (n = 2 to 10, X = Cl-, Br-, BF4-)-carbohydrate-H2O were systemically investigated. For hydrophilic ILs, 1-alkyl-3-methylimidazolium tetrafluoroborate [C(n)mim]BF4 (n = 3, 4), the homogeneous aqueous solution can be induced to separate two aqueous phases by addition of carbohydrate. For hydrophobic ILs, [C(n)mim]BF4 (n = 5 to 10), the mutual solubility with water can be lowered by addition of carbohydrate. While 1-alkyl-3-methyl imidazolium chloride ([C(n)mim]Cl, n = 2 to 10) and 1-alkyl-3-methyl imidazolium bromide ([C(n)mim]Br, n = 2 to 10) aqueous solutions never form aqueous two-phase systems (ATPSs) with carbohydrate in the investigated temperatures ranging from (242.15 to 373.15) K. The high partitioning behavior of phenol in ([C(n)mim]BF4 (n = 3 to 10) (1) + carbohydrate (2) + H2O (3) shows that carbohydrate-tailored {IL + H2O} systems are feasible to be used as extraction systems, especially in biological and environmental engineering. (C) 2009 Elsevier Ltd. All rights reserved.