Solubility of β-cyclodextrin in different mixed solvents

Abstract

The solubility of β-cyclodextrin (β-CD) in ionic liquid/N, N-dimethyl-acetamide (IL/DMAC) mixed solvent and in LiCl/DMAC mixed solvent was investigated at 323.15 K and 353.15 K. The results showed that the solubility of β-CD in IL/DMAC system increased with increasing temperature, but decreased in LiCl/DMAC system. β-CD had the highest solubility in IL/DMAC system with [Cl]- or [Br]- anions. The solubility of β-CD in LiCl/DMAC system was lower than that in IL/DMAC system with [Cl]- or [Br]- anions but higher than that in IL/DMAC system with weak-coordinated anions (e.g [BF4]- or [PF6]-). The effects of substituent groups (benzyl and butyl) of cation and the structure of cations on β-cyclodextrin solubility were also investigated. © China University of Petroleum (Beijing) and Springer-Verlag GmbH 2008.