美国宾州州立大学Lauren D. Zarzar课题组的一项最新研究观察到非互惠的油交换驱动的液滴之间的捕食者-猎物相互作用。 该项研究成果发表在2020年11月16日出版的《自然-化学》上。

该研究团队展示了胶束表面活性剂溶液中，不同化学物质的微尺度油滴之间的趋化信号如何产生类似捕食者-猎物间非交互追逐相互作用。这种相互作用和动态自组织是油在不同组分乳状液滴间整体定向、胶束介导的输运的结果，由混合的自由能驱动。课题组研究人员系统地阐明了化学设计规则，通过改变油和表面活性剂的化学结构和浓度来调节液滴之间的相互作用。

通过实验和模拟相结合的方法，小组还研究了多滴簇的活性行为和动态重组。他们的发现展示了如何用可控的、非互惠的化学趋化相互作用来设计化学最小系统，以产生类似于生物体系的突然自组织和集体行为。

据了解，化学趋化相互作用在自然界中是普遍存在，在多体系统中可导致非互惠的、复杂的突现行为。然而，开发化学机械框架的合成和无生命的实施方案，以产生可调强度和方向性的非互惠相互作用是具有挑战性的。

附：英文原文

Title: Predator–prey interactions between droplets driven by non-reciprocal oil exchange

Author: Caleb H. Meredith, Pepijn G. Moerman, Jan Groenewold, Yu-Jen Chiu, Willem K. Kegel, Alfons van Blaaderen, Lauren D. Zarzar

Issue&Volume: 2020-11-16

Abstract: Chemotactic interactions are ubiquitous in nature and can lead to non-reciprocal and complex emergent behaviour in multibody systems. However, developing synthetic, inanimate embodiments of a chemomechanical framework to generate non-reciprocal interactions of tunable strength and directionality has been challenging. Here we show how chemotactic signalling between microscale oil droplets of different chemistries in micellar surfactant solutions can result in predator–prey-like non-reciprocal chasing interactions. The interactions and dynamic self-organization result from the net directional, micelle-mediated transport of oil between emulsion droplets of differing composition and are powered by the free energy of mixing. We systematically elucidated chemical design rules to tune the interactions between droplets by varying the oil and surfactant chemical structure and concentration. Through the integration of experiment and simulation, we also investigated the active behaviour and dynamic reorganization of multidroplet clusters. Our findings demonstrate how chemically minimal systems can be designed with controllable, non-reciprocal chemotactic interactions to generate emergent self-organization and collective behaviours reminiscent of biological systems. 

DOI: 10.1038/s41557-020-00575-0

Source: https://www.nature.com/articles/s41557-020-00575-0