Mechanical Properties of Self-Assembled Fmoc-Diphenylalanine Molecular Gels

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• 作者：Nikola A. Dudukovic ; Charles F. Zukoski
• 刊名：Langmuir
• 出版年：2014
• 出版时间：April 22, 2014
• 年：2014
• 卷：30
• 期：15
• 页码：4493-4500
• 全文大小：413K
• 年卷期：v.30,no.15(April 22, 2014)
• ISSN：1520-5827

文摘

We explore the phase diagram and mechanical properties of molecular gels produced from mixing water with a dimethyl sulfoxide (DMSO) solution of the aromatic dipeptide derivative fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF). Highly soluble in DMSO, Fmoc-FF assembles into fibrous networks that form gels upon addition of water. At high water concentrations, rigid gels can be formed at Fmoc-FF concentrations as low as 0.01 wt %. The conditions are established defining the Fmoc-FF and water concentrations at which gels are formed. Below the gel boundary, the solutions are clear and colorless and have long-term stability. Above the gel boundary, gels are formed with increasing rapidity with increasing water or Fmoc-FF concentrations. A systematic characterization of the effect of Fmoc-FF and water concentrations on the mechanical properties of the gels is presented, demonstrating that the elastic behavior of the gels follows a specific, robust scaling with Fmoc-FF volume fraction. Furthermore, we characterize the kinetics of gelation and demonstrate that these gels are reversible in the sense that they can be disrupted mechanically and rebuild strength over time.