Blending gelators to tune gel properties and probe anion-induced disassembly

Foster, J.A.; Edkins, R.M.; Cameron, G.J.; Colgin, N.; Fucke, K.; Ridgeway, S.; Crawford, A.G.; Marder, T.B.; Beeby, A.; Cobb, S.L.; Steed, J.W.

Abstract

Blending different low molecular weight gelators (LMWGs) provides a convenient route to tune the properties of a gel and incorporate functionalities such as fluorescence. Blending a series of gelators having a common bis-urea motif, and functionalised with different amino acid-derived end-groups and differing length alkylene spacers is reported. Fluorescent gelators incorporating 1- and 2-pyrenyl moieties provide a probe of the mixed systems alongside structural and morphological data from powder diffraction and electron microscopy. Characterisation of the individual gelators reveals that although the expected α-urea tape motif is preserved, there is considerable variation in the gelation properties, molecular packing, fibre morphology and rheological behaviour. Mixing of the gelators revealed examples in which: 1) the gels formed separate, orthogonal networks maintaining their own packing and morphology, 2) the gels blended together into a single network, either adopting the packing and morphology of one gelator, or 3) a new structure not seen for either of the gelators individually was created. The strong binding of the urea functionalities to anions was exploited as a means of breaking down the gel structure, and the use of fluorescent gel blends provides new insights into anion-mediated gel dissolution.

Citation

Foster, J., Edkins, R., Cameron, G., Colgin, N., Fucke, K., Ridgeway, S., …Steed, J. (2014). Blending gelators to tune gel properties and probe anion-induced disassembly. Chemistry - A European Journal, 20(1), 279-291. https://doi.org/10.1002/chem.201303153

• Journal Article Type: Article
• Publication Date: Jan 3, 2014
• Deposit Date: Jul 16, 2013
• Publicly Available Date: Feb 18, 2014
• Journal: Chemistry - A European Journal
• Print ISSN: 0947-6539
• Electronic ISSN: 1521-3765
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Issue: 1
• Pages: 279-291
• DOI: https://doi.org/10.1002/chem.201303153
• Keywords: Blend, Co-gels, Fluorescence, Orthogonal self-assembly, Supramolecular chemistry.
• Public URL: https://durham-repository.worktribe.com/output/1480581