Polymeric gels have attracted much attention because of their application in cosmetics, medicine, development of smart materials, etc. Superior to polymeric gels are supramolecular gels. They are formed by self-assembly of small monomeric species through noncovalent interactions. This ows to the reversibility of their formation and their degradability, homogeneity, and tunability.

Kana M. Sureshan, Indian Institute of Science, Education, and Research, Thiruvananthapuram, India, have designed and synthesized two organogelators that can be made in one simple step from cheaply available d-mannitol, which can gelate nonpolar solvents and oils. Intermolecular hydrogen bonding was found to be the primary driving force for this gelation process.

The oil gels are strong, highly transparent, and have glass-like refractive indices showing low UV transmittance and high visible transmittance and remarkable self-healing properties. The thermal reversibility of these supramolecular polymers makes them attractive for developing flexible optical devices, e.g. lenses with changing focal lengths.

As these gels are nontoxic and environmentally friendly, they furthermore have advantages over conventional non-biodegradable polymers.

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• Soft Optical Devices from Self-Healing Gels Formed by Oil and Sugar-Based Organogelators,
  Adiyala Vidyasagar, Kishor Handore, Kana M. Sureshan,
  Angew. Chem. Int. Ed. 2011, 50.
  DOI: 10.1002/anie.201103584