title: Recrystallization and shape control of crystals of the organic dye acid green 27 in a mixed solvent.
abstract: Recrystallization of the unstructured dye acid green 27 (AG27) in a mixed solvent of alcohol (ethanol or methanol) and water was systematically studied. The results demonstrated that AG27 crystals with uniform sizes and controllable shapes can be produced by simply changing the volume ratio of ethanol (or methanol) and deionized water (DIW). Rodlike and shuttlelike AG27 crystals can be selectively synthesized. The XRD analyses revealed the periodic structures of the organic crystals. Furthermore, crystallization in another mixed solvent of N,N-dimethylformamide (DMF) and DIW results in the formation of longer fibers with high aspect ratio, which further validates the remarkable effects of mixed solvent on the shape of the AG27 crystals. This method of recrystallization in a mixed solvent is expected to facilitate the synthesis of other functional organic crystals with unusual shapes.
authors.affiliation: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemistry, the School of Chemistry and Materials, University of Science and Technology of China, Hefei 230026, P.R. China.
authors.forename: Huai-Ping
authors.initials: HP
authors.lastname: Cong
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Yu