Lithium chloride-induced organogel transformed from precipitate based on cyclodextrin complexes

This paper describes a novel heat-set organogel transformation which could be triggered by lithium chloride (LiCl) from precipitate for the first time. The system was prepared with beta-cyclodextrin (beta-CD) and triphenylphosphine (Ph3P) in N,N-dimethylformamide (DMF). The system as an original transparent solution at room temperature could turn into precipitation by heating. Subsequently, the precipitation turned into organogel instantly based on the injection of LiCl into the system. SEM measurement revealed that the precipitate and gel systems have different microstructures. IR and XRD measurements revealed that the inclusion complexes formed by beta-CDs and Ph3P were arranged in cage structures in the precipitate and channel structures in the gel. Molecular dynamics simulations were performed both on the formation of the precipitate and gel models in this system, which were consistent with the test results. (C) 2011 Published by Elsevier B.V.