Ionic liquids have remarkable properties and are commonly harnessed for green chemistry, lubrication, and energy applications. In this paper, we study a thermoresponsive ionic liquid (IL) solution which has the property of phase separating above a critical temperature, an interesting feature for the recovery of the IL-rich phase. For this purpose, we generate a temperature gradient in a microfluidic cavity where the confinement strengthens wetting effects and enhances the demixing. We show that the phase separation is performed by the joint effects of sedimentation and thermocapillary actuation giving rise to a three-dimensional flow structure, which is quantitatively captured by our model. Altogether those mechanisms lead to the accumulation of the wetting phase near the heating source. We believe this work will find applications in the recycling of ionic liquids.

中文翻译：

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温度梯度辅助下的离子液体混合物的相分离

离子液体具有卓越的性能，通常用于绿色化学，润滑和能源应用。在本文中，我们研究了一种热响应性离子液体（IL）溶液，该溶液具有高于临界温度的相分离特性，这是回收富含IL的相的有趣特征。为此，我们在微流腔中产生温度梯度，其中限制会增强润湿效果并增强分解效果。我们表明，相分离是通过沉降和热毛细管驱动的联合效应进行的，从而产生了三维流动结构，该流动结构由我们的模型定量捕获。总而言之，这些机理导致了润湿相在热源附近的积累。