title: Fluorescent magnesium(II) coordination polymeric hydrogel.
abstract: A pH and mechano-responsive coordination polymeric gel was developed without the use of long chain hydrophobic groups. The hydrogel was synthesised by reacting the aqueous solution of Mg2+ with the basic aqueous solution of N-(7-hydroxyl-4-methyl-8-coumarinyl)-alanine. The gelation is attributed to the self-aggregation of 1D coordination polymers to form 3D nanostructures through non-covalent interactions to entrap water molecules. The freeze-dried hydrogel exhibits a fibrillar network structure with a uniform ribbon shape. UV/vis absorption studies illustrate that the hydrogel displays a typical pi-pi* transition. The fluorescence intensity of the hydrogel is enhanced drastically with a longer lifetime upon gel formation. Mechanical analysis including dynamic oscillation on shear, steady shear and creep (retardation-relaxation) testing have been performed to elucidate the supramolecular nature of the 3D assembly. Together with the viscoelastic properties and biocompatibility, the Mg2+ hydrogel may find utility as a novel soft material in biomedical applications.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive, 117543 (Singapore), Fax: (+65) 6779-1691.
authors.forename: Wei Lee
authors.initials: WL
authors.lastname: Leong
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive, 117543 (Singapore), Fax: (+65) 6779-1691.
authors.forename: Sudip K
authors.initials: SK
authors.lastname: Batabyal
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive, 117543 (Singapore), Fax: (+65) 6779-1691.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kasapis
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive, 117543 (Singapore), Fax: (+65) 6779-1691.
authors.forename: Jagadese J
authors.initials: JJ
authors.lastname: Vittal
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