Scholz Christian, Ldov Anton, Pöschel Thorsten, Engel Michael, Löwen Hartmut
Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
Institute for Multiscale Simulation Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
Sci Adv. 2021 Apr 14;7(16). doi: 10.1126/sciadv.abf8998. Print 2021 Apr.
Surfactant molecules migrate to interfaces, reduce interfacial tension, and form micelles. All of these behaviors occur at or near equilibrium. Here, we describe active analogs of surfactants that operate far from equilibrium in active chiral fluids. Unlike molecular surfactants, the amphiphilic character of surfactants in active chiral fluids is a consequence of their activity. Our fluid of choice is a mixture of spinners that demixes into left-handed and right-handed chiral fluid domains. We realize spinners in experiment with three-dimensionally printed vibrots. Vibrot surfactants are chains of vibrots containing both types of handedness. Experiments demonstrate the affinity of double-stranded chains to interfaces, where they glide along and act as mixing agents. Simulations access larger systems in which single-stranded chains form spinning vesicles, termed rotelles. Rotelles are the chiral analogs of micelles. Rotelle formation is a ratchet mechanism catalyzed by the vorticity of the chiral fluid and only exist far from equilibrium.
表面活性剂分子迁移到界面，降低界面张力，并形成胶束。所有这些行为都发生在平衡状态或接近平衡状态时。在此，我们描述了在活性手性流体中远离平衡运行的表面活性剂活性类似物。与分子表面活性剂不同，活性手性流体中表面活性剂的两亲特性是其活性的结果。我们选择的流体是一种旋转体混合物，它会分离成左手性和右手性手性流体域。我们在实验中用三维打印的振动体实现了旋转体。振动体表面活性剂是包含两种手性的振动体链。实验证明了双链对界面的亲和力，它们在界面上滑动并充当混合剂。模拟研究了更大的系统，其中单链形成旋转囊泡，称为旋转体。旋转体是胶束的手性类似物。旋转体的形成是一种由手性流体的涡度催化的棘轮机制，并且仅在远离平衡时存在。
