Fuelled chemical systems have considerable functional potential that remains largely unexplored. Here we report an approach to transient amide bond formation and use it to harness chemical energy and convert it to mechanical motion by integrating dissipative self-assembly and the Marangoni effect in a source–sink system. Droplets are formed through dissipative self-assembly following the reaction of octylamine with 2,3-dimethylmaleic anhydride. The resulting amides are hydrolytically labile, making the droplets transient, which enables them to act as a source of octylamine. A sink for octylamine was created by placing a drop of oleic acid at the air–water interface. This source–sink system sets up a gradient in surface tension, which gives rise to a macroscopic Marangoni flow that can transport the droplets in solution with tunable speed. Carbodiimides can fuel this motion by converting diacid waste back to anhydride. This study shows how fuelling at the molecular level can, via assembly at the supramolecular level, lead to liquid flow at the macroscopic level.

燃料化学系统具有相当大的功能潜力，但在很大程度上仍未得到探索。在这里，我们报告了一种瞬时酰胺键形成的方法，并通过在源-汇系统中集成耗散自组装和马兰戈尼效应来利用化学能并将其转化为机械运动。液滴是辛胺与 2,3-二甲基马来酸酐反应后通过耗散自组装形成的。所得酰胺具有水解不稳定性，使液滴具有瞬态性，这使它们能够充当辛胺的来源。通过在空气-水界面处放置一滴油酸来形成辛胺的汇。这种源-汇系统在表面张力中建立了一个梯度，从而产生宏观马兰戈尼流，可以以可调的速度在溶液中运输液滴。碳二亚胺可以通过将二酸废物转化回酸酐来推动这种运动。这项研究表明，分子水平的燃料如何通过超分子水平的组装导致宏观水平的液体流动。