## Overview

The manuscript by Fan et al. investigates liquid–liquid phase separation (LLPS) in droplet mixtures on slides.

When surfactants are present, the LLPS exhibits a core–shell morphology, with the organic phase forming the inner core.

The study is interesting and provides valuable insight into LLPS behavior; however, as with many LLPS studies, its direct impact on atmospheric aerosol particles is not quantified—though a plausible mechanism is discussed.

Overall, this is a solid and useful contribution that establishes a foundation for future experimental and modeling investigations.

## Comments

**Figure 3:**

It would be worthwhile to discuss the pure surface tension of 1,2,6-hexanetriol and how it compares to lower–surface-tension organics or typical secondary organic aerosols.

This discussion could be added near Figure 3 or incorporated into the main discussion section.

My reasoning is that a lower–surface-tension organic compound would likely remain as the particle-engulfing phase for a longer period (as surfactant concentration increases) and may not transition to a core–shell morphology as readily.