Miscible liquids can phase separate in response to a composition change. In bulk fluids, the demixing begins on molecular-length scales, which coarsen into macroscopic phases. By contrast, confining a mixture in microfluidic droplets causes sequential phase separation bursts, which self-organize into rings of oil and water to make multilayered emulsions. The spacing in these nonequilibrium patterns is self-similar and scale-free over a range of droplet sizes. We develop a modified Cahn–Hilliard model, in which an immiscibility front with stretched exponential dynamics quantitatively predicts the spacing of the layers. In addition, a scaling law predicts the lifetime of each layer, giving rise to a stepwise release of inner droplets. Analogously, in long rectangular capillaries, a diffusive front yields large-scale oil and water stripes on the time scale of hours. The same theory relates their characteristic length scale to the speed of the front and the rate of mass transport. Control over liquid–liquid phase separation into large-scale patterns finds potential material applications in living cells, encapsulation, particulate design, and surface patterning.

混溶的液体可以响应于组成变化而相分离。在散装流体中，混合从分子尺度开始，然后粗化为宏观阶段。相比之下，将混合物限制在微流体液滴中会引起相继的相分离爆发，其自组织成油和水的环，从而制成多层乳液。在液滴尺寸范围内，这些非平衡模式中的间距是自相似且无标度的。我们开发了一种改进的Cahn-Hilliard模型，其中具有扩展指数动力学的不混溶前沿定量预测了层的间距。此外，结垢定律可预测每一层的寿命，从而逐步释放内部液滴。类似地，在长矩形毛细管中，在数小时的时间尺度上，扩散锋面会产生大规模的油水条纹。相同的理论将它们的特征长度尺度与前沿的速度和传质速率相关。将液-液相分离成大规模图案的控制发现了活细胞，封装，颗粒设计和表面图案化方面的潜在材料应用。