Long-Lived Foams Stabilized by a Hydrophobic Dipeptide Hydrogel

Research output: Contribution to journalJournal article – Annual report year: 2016Researchpeer-review

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DOI

  • Author: Li, Tao

    University of Edinburgh, United Kingdom

  • Author: Nudelman, Fabio

    University of Edinburgh, United Kingdom

  • Author: Tavacoli, Joe

    University of Edinburgh

  • Author: Vass, Hugh

    University of Edinburgh, United Kingdom

  • Author: Adams, Dave J.

    University of Liverpool, United Arab Emirates

  • Author: Lips, Alex

    University of Edinburgh, United Kingdom

  • Author: Clegg , Paul S.

    University of Edinburgh, United Kingdom

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A hydrogel of hydrophobic dipeptides can be used to create a wet foam with long-term stability. The dipeptide molecules self-assemble into fiber-like networks (due to the presence of metal ions) both at air-water interfaces and in the continuous phase. The former creates an interfacial film stabilizing the air bubbles while the latter forms a bulk gel, which prevents bubble movement and retards growth. If the storage modulus (G) of the bulk hydrogel is sufficiently high it can stop the coarsening of the air bubbles and thus dramatically improve the stability of the foam. Cryogenic scanning electron microscopy and Raman spectra reveals the width of the fibers (200 nm) and that they are held together by hydrogen bonds. In the absence of bubbles, phase separation is observed between a hydrogel and a water-rich phase; in the foam this can be suppressed provided that the concentration of dipeptides and metal ions are sufficiently high. It is speculated that the resistance of the bubble arrangement to compaction and hence further drainage arrests the process of phase separation. This foam system has the advantages of long stability, low cost, as well as easy preparation; therefore, it has potential applications in food manufacturing, drug delivery, and personal care industries.
Original languageEnglish
Article number1500601
JournalAdvanced Materials Interfaces
Volume3
Issue number3
Number of pages8
ISSN2196-7350
DOIs
Publication statusPublished - 2016
Externally publishedYes
CitationsWeb of Science® Times Cited: No match on DOI

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