论文标题
用活性流体控制液态液相行为
Controlling liquid-liquid phase behavior with an active fluid
论文作者
论文摘要
二进制液体的混合是一种无处不在的过渡,它使用建立的热力学形式主义来解释,该形式需要在整个相边界上平等的密集热力学参数。当二元流体混合物远离平衡时(例如,通过外部剪切流动)驱动二元流体混合物时,也会发生解散转变。然而,预测非平衡性非平衡条件下的解散转变仍然是一个挑战。我们使用基于内部驱动的微管的活性流体将有吸引力的DNA纳米级分子的液态液相分离(LLP)从平衡中驱逐出来。活性降低了临界温度并缩小了共存浓度,但仅当液滴与重新配置活性流体之间存在机械键时。在数值模拟中观察到类似的行为,表明液态液相分离的活性抑制是活性LLP的一般特征。我们的工作描述了一个通过反馈控制来构建软件材料的平台,同时还提供了对细胞生物学的见解,在这些平台中,相位分离成为无处不在的自组织原理。
Demixing of binary liquids is a ubiquitous transition, which is explained using a well-established thermodynamic formalism that requires equality of intensive thermodynamics parameters across the phase boundaries. Demixing transitions also occur when binary fluid mixtures are driven away from equilibrium, for example, by external shear flow. Predicting demixing transition under non-equilibrium non-potential conditions remains, however, a challenge. We drive liquid-liquid phase separation (LLPS) of attractive DNA nanostar molecules away from equilibrium using an internally driven microtubule-based active fluid. Activity lowers the critical temperature and narrows the coexistence concentrations, but only when there are mechanical bonds between the liquid droplets and the reconfiguring active fluid. Similar behaviors are observed in numerical simulations, suggesting that activity suppression of liquid-liquid phase separation is a generic feature of active LLPS. Our work describes a platform for building soft active materials with feedback control while also providing insight into cell biology, where phase separation emerged as a ubiquitous self-organizational principle.