title: Reversible heat-set organogel based on supramolecular interactions of beta-cyclodextrin in N,N-dimethylformamide.
abstract: This paper describes the first reversible, heat-set organogel based on the supramolecular interactions of beta-cyclodextrin (beta-CD). The gel was prepared by interaction of diphenylamine (DPA) with beta-CD and lithium chloride in N,N-dimethylformamide (DMF). In this gel system, DPA could be gelated in DMF as the temperature increased and then dissolved again as the temperature decreased. In the microscopic structure of gel, beta-CDs play a key role in the formation of nanorods and microfibers. Some important features of the gel were observed. (1) The system is a multicomponent solution, in which each of the four components is required for the organogelation property. (2) The system is a reversible, thermo-responsive organogel composed of small organic molecules. When the temperature is lower than T(gel), the gel transforms back into a solution. The reversible thermo-transition was confirmed by differential scanning calorimetry (DSC). The gel system is responsive to the concentration of LiCl. No gel was formed without LiCl. The stimuli responses of the system with other salts such as KCl and NaCl were weaker than with LiCl. (4) The system is responsive to the addition of guest molecules. The structures and sizes of the guest molecules could influence the gel formation. Generally, T(gel) decreased by adding guest molecules in the gel system, but some guest molecules, whose structures are exactly fitted to the cavity of CDs, could prevent gel formation. This work may provide new avenues in delivery of functional molecules as well as design of intelligent materials and biomaterials.
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Guangyan
authors.initials: G
authors.lastname: Du
authors.forename: Hui
authors.initials: H
authors.lastname: Yan
authors.forename: Hongyao
authors.initials: H
authors.lastname: Wang
authors.forename: Huacheng
authors.initials: H
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: An
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zhao
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.forename: Feiei
authors.initials: F
authors.lastname: Xin
authors.forename: Li
authors.initials: L
authors.lastname: Kong
authors.forename: Yueming
authors.initials: Y
authors.lastname: Li
authors.forename: Aiyou
authors.initials: A
authors.lastname: Hao
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Hao
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D004126:Dimethylformamide; D004159:Diphenylamine / Q000737:chemistry; D005559:Formamides / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D006358:Hot Temperature; D018021:Lithium Chloride / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D005559:Formamides; D005782:Gels; D047392:beta-Cyclodextrins; D004126:Dimethylformamide; D004159:Diphenylamine; D018021:Lithium Chloride; C031215:betadex