Light-Harvesting Supramolecular Hydrogels Assembled from Short-Legged Cationic L-Glutamate Derivatives and Anionic Fluorophores

Nakashima, Torahiko; Kimizuka, Nobuo

doi:10.1002/1521-4095(20020816)14:16<1113::aid-adma1113>3.0.co;2-u

Cited by 159 publications

(108 citation statements)

References 8 publications

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“…A hydrogel obtained from a mixture of cationic glutamate derivatives, LH6 or LH7 (Chart 9), and the anionic naphthalene sulfonate (5 mM) and anthracene sulfonate (1 mol%) exhibited light harvesting. 30 The naphthalene anions, believed to be organized on the surface of the gel fibres, channelled their excitation energy to the anthracene anions present in the aqueous pool resulting in the emission from anthracene.…”

Section: Light Harvestingmentioning

confidence: 99%

Supramolecular gels: Functions and uses

2005

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In recent years there has been immense interest in studying gels derived from low molecular mass gelators (supramolecular, or simply molecular gels). The motivation for this is not only to understand the fundamental aggregate structures in the gels at different length scales, but also to explore their potential for futuristic technological applications. Gels have been made sensitive to external stimuli like light and chemical entities by incorporating a spectroscopically active or a receptor unit as part of the gelator molecule. This makes them suitable for applications such as sensing and actuating. The diversity of gel structural architectures has allowed them to be utilized as templates to prepare novel inorganic superstructures for possible applications in catalysis and separation. Gels derived from liquid crystals (anisotropy gels) that can act as dynamically functional materials have been prepared, for example, for (re-writable) information recording. Supramolecular gels can be important in controlled release applications, in oil recovery, for gelling cryogenic fuels etc. They can also serve as media for a range of applications. This tutorial review highlights some of the instructive work done by various groups to develop smart and functional gels, and covers a wide spectrum of scientific interest ranging from medicine to materials science.

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Section: Light Harvestingmentioning

confidence: 99%

Supramolecular gels: Functions and uses

2005

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“…16,38,39 Table 1 summarizes their morphology and gel-to-liquid-crystalline phase transition behaviors in aqueous bilayers. Amphiphile 1 formed vesicles in water, with a gelto-liquid-crystalline phase transition temperature T c of 33 1C.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, amphiphiles 2 and 3 showed higher T c (69 1C for 2, 87 1C for 3), indicating that the introduction of amide linkages and longer alkyl chains strengthens intermolecular interactions and consequently enhances the thermal stability of the gel phase. 16,38 Dispersion behavior of amphiphiles 1-4 in ILs Amphiphiles 1-4 were dispersed in ILs (C 1 OC 1 mimTFSA and C 4 mimTFSA, Figure 1) by ultrasonication for a few minutes at room temperature. Table 2 summarizes the appearance of 1-4 (10 mM) in ILs and reports the dissolution temperatures of the ionogels T GS .…”

Section: Resultsmentioning

confidence: 99%

“…We have previously reported that amphiphile 2 alone in water gives a viscous dispersion of the bilayer membrane, which becomes gelatinized upon the addition of hydrophobic aromatic anions. 38 The hydrophobic anions effectively shielded the electrostatic repulsion between nanofibers and promoted their contacts, resulting in the formation of hydrogels. In this case, the electrostatic repulsion between charged fibrous nanostructures in ILs should also be effectively screened by the adsorption of TFSA ions, resulting in the observed physical gelation of ILs.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Controlled self-assembly of amphiphiles in ionic liquids and the formation of ionogels by molecular tuning of cohesive energies

Nakashima

Kimizuka

2012

Polym J

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In this paper, the self-assembling characteristics of a series of L-glutamate-based ammonium amphiphiles are studied in ionic liquids (ILs). These cationic amphiphiles are dispersible in imidazolium ILs with bis((trifluoromethyl)sulfonyl)amide (TFSA) anion. Amphiphiles-containing didodecyl ester or short dioctyl amide groups were molecularly dispersed in conventional 1-butyl-3-methylimidazolium TFSA, whereas they formed bilayer membranes when they were dispersed in polar, ether linkageintroduced IL. Thus, the modification of ILs exerts a crucial influence on amphiphilic self-assembly. Enhancement of the intermolecular interactions of L-glutamate amphiphiles is achieved by introducing multiple amide bonds and longer alkyl chains, which leads to better self-assembling properties. These amide-enriched amphiphiles form fibrous bilayer assemblies even in conventional ILs with low cohesive energy densities. These observations confirm that the formation of bilayer membranes in ILs is a general phenomenon when the solute molecules have the appropriate 'ionophilic/ionophobic' nature.

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“…Van der Waals forces [15], hydrogen bonding [11,16], ionic bonding [17] and combination of these forces [18]. Another important factor for hydrogelling is the delicate hydrophilic/hydrophobic balance of the compounds.…”

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confidence: 99%