Necklace of surfactant / Flower of surfactant —Haoyu Wang, Imperial College London

Anionic surfactant, Sodium Linear Alkylbenzene Sulfonate (NaLAS), forms flow-shape, pill-shape and necklace-shape at the liquid-air interface during the cooling process.

https://fluids.ac.uk/files/05_Haoyu_Wang_composite.1605636174.jpg