Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
Langmuir. 2012 Jun 26;28(25):9259-66. doi: 10.1021/la301442f. Epub 2012 Jun 12.
We developed novel supramolecular gelators with simple molecular structures that could harden a broad range of solvents: aqueous solutions of a wide pH range, organic solvents, edible oil, biodiesel, and ionic liquids at gelation concentrations of 0.1-2 wt %. The supramolecular gelators were composed of a long hydrophobic tail, amino acids and gluconic acid, which were prepared by liquid-phase synthesis. Among seven types of the gelators synthesized, the gelators containing L-Val, L-Leu, and L-Ile exhibited high gelation ability to various solvents. These gelators were soluble in aqueous and organic solvents, and also in ionic liquids at high temperature. The gelation of these solvents was thermally reversible. The microscopic observations (TEM, SEM, and CLSM) and small-angle X-ray scattering (SAXS) measurements suggested that the gelator molecules self-assembled to form entangled nanofibers in a large variety of solvents, resulting in the gelation of these solvents. Molecular mechanics and density functional theory (DFT) calculations indicated the possible molecular packing of the gelator in the nanofibers. Interestingly, the gelation of an ionic liquid by our gelator did not affect the ionic conductivity of the ionic liquid, which would provide an advantage to electrochemical applications.
我们开发了具有简单分子结构的新型超分子凝胶剂，能够使广泛范围的溶剂固化：在凝胶浓度为 0.1-2wt%时，宽 pH 范围的水溶液、有机溶剂、食用油、生物柴油和离子液体。超分子凝胶剂由长疏水尾、氨基酸和葡萄糖酸组成，通过液相合成制备。在合成的七种凝胶剂中，含有 L-Val、L-Leu 和 L-Ile 的凝胶剂对各种溶剂具有高的凝胶能力。这些凝胶剂可溶于水相和有机溶剂，也可在高温下溶于离子液体。这些溶剂的凝胶化是热可逆的。微观观察（TEM、SEM 和 CLSM）和小角 X 射线散射（SAXS）测量表明，凝胶剂分子在各种溶剂中自组装形成缠结的纳米纤维，导致这些溶剂的凝胶化。分子力学和密度泛函理论（DFT）计算表明了凝胶剂在纳米纤维中的可能分子堆积。有趣的是，我们的凝胶剂使离子液体凝胶化不会影响离子液体的离子电导率，这将为电化学应用提供优势。
