Particle Size Determines the Shape of Supraparticles in Self-Lubricating Ternary Droplets

Supraparticles are large clusters of much smaller colloidal particles. Controlling the shape and anisotropy supraparticles can enhance their functionality, enabling applications in fields such as optics, magnetics, medicine. The evaporation self-lubricating ouzo droplets is an easy efficient strategy to create supraparticles, overcoming problem “coffee-stain effect” during drop evaporation. Yet, parameters that control formed evaporating not fully understood. Here, we show size particles determines supraparticle. We compared made seven different sizes spherical silica particles, namely from 20 1000 nm, mixtures small at mixing ratios. Specifically, our situ measurements revealed supraparticle formation proceeds via a flexible shell rapidly moving interfaces droplet. time tc0 when ceases shrink loses its flexibility closely related A lower tc0, observed for leads flat pancake-like supraparticle, contrast more curved American football-like larger Furthermore, using mixture obtained display spatial variation particle distribution, with colloids forming outer surface Our findings provide guideline controlling distribution by simply ternary drops filled