# Tuning contact line dynamics and deposition patterns in volatile liquid mixtures

## TL;DR

This paper investigates how adding a non-volatile liquid to a volatile one affects contact line dynamics and deposition patterns, revealing tunable regimes influenced by Marangoni forces and contact angles.

## Contribution

It demonstrates the ability to control deposition patterns in volatile liquid mixtures by tuning contact angles and solutal Marangoni forces, revealing distinct regimes of behavior.

## Key findings

- Large Marangoni forces lead to finger-like instabilities and thin film deposition.
- Small Marangoni forces result in pearl-like droplets with quasi-crystalline arrangements.
- Deposition patterns can be tuned by adjusting the solute contact angle on the substrate.

## Abstract

The spreading of a pure, volatile liquid on a wettable substrate has been studied in extensive detail. Here we show that the addition of a miscible, non-volatile liquid can strongly alter the contact line dynamics and the final liquid deposition pattern. We observe two distinct regimes of behavior depending on the relative strength of solutal Marangoni forces and surface wetting. Finger-like instabilities precede the deposition of a sub-micron thick film for large Marangoni forces and small solute contact angles, whereas isolated, pearl-like drops emerge and are deposited in quasi-crystalline patterns for small Marangoni forces and large solute contact angles. This behavior can be tuned by directly varying the contact angle of the solute liquid on the solid substrate.