Manipulating liquid-liquid phase separation using patterned flow

TL;DR

This paper demonstrates that patterned fluid flow can precisely control liquid-liquid phase separation, enabling manipulation of droplet formation, size, arrangement, and kinetics through theoretical and numerical methods.

Contribution

It introduces the use of tailored patterned flow as a versatile tool to manipulate LLPS, advancing control beyond previous fluid flow approaches.

Findings

Flow structures can capture and pin droplets.

Droplet sizes can be finely tuned.

Periodic droplet arrays can be assembled and restructured.

Abstract

The precise control of liquid-liquid phase separation (LLPS) is the key to developing cutting-edge technologies that benefit diverse disciplines. Fluid flow was found to be capable of controlling the structure and effective temperature of LLPS, but the extent and precision of control were less than optimal. In this article, we propose that patterned flow can be employed as a generic tool to manipulate LLPS effectively. By combining theoretical modeling and numerical simulations, we demonstrate that flows with tailor-made structures can become functional, allowing us to control diverse aspects of LLPS. Typical examples include the capture and pinning of droplets, fine-tuning of droplet sizes, forced assembly of periodic droplet arrays, and the remodeling of the kinetics and structure of phase separation. These manipulations are grounded on the redistribution of chemical potential by the structured flow. Our results not only can lead to potential LLPS-based technologies, but also highlight the rich behavior of LLPS introduced by the patterned flow.